While a diagnosis of androgenetic alopecia does give you a complete explanation of your problem and its cause (although there is no chance of a cure), a diagnosis of diffuse hair loss is only a description of what is going on on your head.
Diffuse alopecia often presents a detective challenge to doctors and patients in their search for the cause. However, the chances of stopping the hair loss and even reversing the hair loss as soon as the cause is identified are quite good. In many cases, however, diffuse alopecia also simply disappears spontaneously – namely whenever the factors causing it were only effective for a short time.
The causes of diffuse hair loss can be quite different. The most common causes are probably stress, hormone fluctuations, high fever, side effects of medication and thyroid disease. Nutrient deficiency can also play a role in rare cases.  The following section will give you more details about the range of causes of diffuse alopecia.
Diffuse hair loss due to medication
It is well known that chemotherapy of tumor diseases (as well as radiation) causes extensive and very short-term hair loss (anagen effluvium) But disorders of hair growth are also among the known side effects of many other drugs. If you go to a dermatologist with suspected hair loss, the question of the medications you are taking regularly or have taken in recent months will therefore also be asked in the anamnesis interview.
Disorders of hair growth can be caused by, among other things, blood pressure lowering drugs (beta-blockers and ACE inhibitors), blood lipid reducers, anticoagulants (blood thinners), cytostatic drugs such as methotrexate, which are also used as a low-dose basic therapy for the permanent treatment of rheumatic and other autoimmune diseases, antiepileptic drugs, various antibiotics and psychotropic drugs  as well as by the so-called biologicals (biotechnologically produced biomolecules that act as messenger and signal substances in cells and tissues and are used in tumor therapy and autoimmune diseases). Indeed, there are even reports of hair loss for such widely used drugs as some of the non-steroidal painkillers and anti-inflammatory drugs (ibuprofen, ketoprofen, etc.)  Some correlations appear at first glance to be downright absurd, but are well documented: For example, eye drops with the active ingredient timolol, which are prescribed for glaucoma, can cause very dramatic cases of diffuse hair loss of the scalp .
The concrete mechanism of action by which they cause hair loss is only known or suspected for a few classes of active ingredients – for example, anticoagulants are said to impair the blood supply to the hair papilla and ACE inhibitors cause zinc deficiency. For most active ingredients it is unclear how they influence hair growth – the connection is simply considered proven if discontinuing the drug leads to an improvement.
Here once again in list form: the drugs whose known side effects include hair loss. For most of these drugs, however, hair loss is a rarely or very rarely observed side effect. Please also note: Such drug effects on the hair are usually the so-called telogen effluvium. They therefore do not appear immediately after taking the drug, but with a time delay of two to four months.
- Blood pressure reducers
- Blood Thinner
- Blood lipid reducer
- Retinoids (Azitretin, Etretinate)
- some antibiotics
- Psychotropic drugs (including antidepressants)
- Epilepsy medication
- Hormone-containing medication (contraceptive pill – especially if the progestin content is high, hormone replacement therapy, thyroid medication if not optimally adjusted)
- Glaucoma eye drops
- Anti-inflammatory analgesics
The diagnosis of drug-induced hair loss is complicated by the fact that such problems by no means occur with all users of the drugs in question, but are usually only rare side effects, that intensifying effects can result from a combination of different drugs – and that the effect on hair growth is usually considerably delayed. If the hair loss occurs three to four months after the start of medication, yes, if the medication was only taken for a short time and in the meantime has long since been discontinued, the correct diagnosis is not easy (and often a bit of a guess).
Typical damage, especially in the root area of the hair, indicates toxic processes. An increased proportion of so-called dystrophic (=growth-disturbed) hair should be mentioned here: Experienced dermatologists can easily distinguish these damaged hairs in the trichogram from normal anagen and telogen hairs by means of a pencil-like narrowing in the root area.
The good news is that hair loss through medication is almost never permanent. Exceptions are highly effective cytostatic drugs used for the aggressive chemotherapy of certain tumours and to suppress the immune system after bone marrow transplants – such substances can cause permanent damage to the hair follicles. In all other cases, all you need is a little patience after stopping the drugs: Due to the length of the follicle cycle, it usually takes about half a year until the hair becomes visibly thicker again.
However, if you have to take the medication that is suspected of damaging your hair permanently, this knowledge is unfortunately of little help. It may then be possible to switch to a different active ingredient. It may also be advisable to carry out an exact screening of the medication you are taking: Where is a dose reduction conceivable, which ones might even be dispensable? Many medications are only prescribed against side effects of other drugs. If you are suffering from new side effects, a re-evaluation of your entire medication plan may be advisable.
Diffuse hair loss due to hormone fluctuations
Hormones influence hair growth – and accordingly, the normal fluctuations of various hormone levels can also lead to disturbances of the hair follicle cycle. In women, the hormones undergo relatively complicated changes in the monthly rhythm as well as in the different phases of life, so women are particularly affected by such hair problems.
Hormone-related hair loss can occur:
- during puberty
- while breast-feeding
- after starting regular use of contraceptives, after switching to another preparation or after discontinuing the pill
- when using a hormone coil
- menopausal and postmenopausal
There are phases of life in which a woman’s hair grows particularly thick and beautiful (especially during pregnancy this is often the case), and other phases in which the hair is slightly less thick. In the transitional phases (i.e. after childbirth – post-partum hair loss), hair loss may temporarily increase while the new balance is established. As long as these transitional phases are temporary and the hair density is still within the normal range, such phenomena are not a cause for concern. A dermatologist will not see any reason for treatment here, but will advise to wait and see. Possibly he will recommend supporting teas, possibly also food supplements with herbal estrogens (phytohormones, e.g. red clover).
(By the way, there is a quite carefully researched critical article that slimly doubts the existence of postpartum effluvium: The authors argue that the data of the often cited studies, on the basis of which the phenomenon mentioned in every textbook was actually proven, are actually not very impressive ).
Significant diffuse hair loss in connection with the permanent changes during menopause is, however, often permanent: As a result of the lowered estrogen level, many women experience a noticeable thinning of the hair.
30 to 50 percent of postmenopausal women also develop female type androgenetic alopecia. These women therefore often have a diffuse thinning of the hair on the entire head caused by the low estrogen level and additionally the typical pattern of female alopecia caused by androgens, i.e. further thinning concentrated on the crown and hairline.
The estrogen-deficient diffuse hair loss during the menopause usually responds to hormone replacement therapy (but beware: the treatment of typical menopausal symptoms with synthetic estrogens or combined preparations containing estrogens and progestins has been criticised for some years, among other things because it significantly increases the risk of various types of cancer). An alternative to hormone replacement therapy is phytohormones, hormone-like substances from plant sources.
It is possible that phytohormones can also regulate symptoms such as hair loss in women of reproductive age, which result from fluctuations in the hormone balance. However, the scientific evidence for this is still very patchy. Experiments with teas or a deliberate intake of phytoestrogen-containing foods can be affirmed just as much as the frequently recommended supplementation with zinc or biotin (for which there is also no clear evidence). Problematic side effects are not to be expected.
Minoxidil is a very promising treatment option in cases of pronounced hormone-induced thinning of the hair.
Diffuse hair loss due to thyroid diseases
Over- and under-functioning of the thyroid gland influence the body’s hormone balance and often trigger diffuse hair loss. Once the thyroid gland disease has been diagnosed and treatment has been initiated, hair growth returns to normal after some time. However, a little more patience is required here: unfortunately, due to the length of the follicular phases, the hair reacts to the therapy much more slowly than other body tissues.
Often thyroid gland diseases of origin are autoimmune diseases (Hashimoto: hypothyroidism caused by autoimmune processes, Graves’ disease: hyperthyroidism caused by autoimmune processes). The body’s immune system directs its aggression against the body’s own tissue, in this case the thyroid gland. If there is an existing tendency to autoimmune diseases, other tissues may also be affected. People with autoimmune diseases of the thyroid gland have a slightly higher risk of developing circular hair loss (Alopecia areata) caused by autoimmune processes. These are then two different sites, so to speak: While treatment of the thyroid gland normalizes diffuse hair loss, alopecia areata does not respond to it.
Diffuse hair loss as a result of thyroid disease shows in the trichogram an increased proportion of hair in the telogen phase, but usually no dystrophic hair with damage in the root area. This diagnostic picture now also occurs with many other forms of hair loss, and therefore has no diagnostic value for the thyroid disease itself. However, the trichogram can be helpful in ruling out other causes of hair loss (especially side effects of drugs): in these cases, an increased proportion of dystrophic hairs can be expected.
Some thyroid diseases that are otherwise still largely symptom-free have already been diagnosed because those affected were worried about thinning hair. In most cases, however, thyroid dysfunction is accompanied by a variety of symptoms, many of which are more pressing and worrying than brittle and/or thinning hair. The diagnosis of thyroid disease based on a blood test usually provides the answer to why the hair is not doing well.
However, due to the time delay with which the hair reacts to changes in its state of health, it is possible that the peak of the hair-related symptoms of thyroid disease may fall during the time when treatment has already been initiated. Those affected then sometimes suspect that the thyroid medications (very often radioiodine treatment is suspected in cases of hyperthyroidism) could cause the hair loss. Doctors consider this unlikely; in any case, such hair loss would be temporary.
The prospects of getting full hair again are very good in the case of a thyroid dysfunction that is well adjusted with medication. However, fluctuations in the course of the disease and/or changes in the treatment regime may result in new episodes of increased hair loss.
Anyone suffering from a thyroid dysfunction and having problems with their hair should in any case also keep an eye on the general nutrient situation of their body: Often, hypothyroidism is associated with secondary nutrient deficiencies due to poorer nutrient absorption.
Diffuse hair loss due to high fever
High fever is also one of the triggers of temporary diffuse hair loss – studies suspect this cause in 12 to 33% of the cases investigated.  However, the home country and social class of the study participants played a major role in the frequency of fever-induced effluviums: countries in which infectious diseases such as dengue fever, typhoid, malaria or tuberculosis occur comparatively frequently in certain population groups naturally have higher values than countries and classes in which there are hardly any widespread, highly febrile infections apart from influenza.
The cause of the fever seems to be largely unimportant for hair loss, the only decisive factors being the temperature level and the duration of the fever episode. Hair loss typically begins two to three months after the febrile illness and continues for several weeks. It is a telogenous effluvium: triggered by the fever, many hair follicles have synchronously entered the telogen phase from the anagen (growth) phase and are now gradually falling out. Those affected notice a conspicuously increased hair loss when combing, washing or at night.
Diffuse hair loss due to fever shows the typical symptoms of telogen effluvium.
The trichogram does not show any damage to the hair roots, but an abnormally high proportion of telogen hair (25% or more is considered a guideline). The hair plucking test is also very striking.
However, these general symptoms do not allow us to say with certainty that the hair loss is actually the result of the previous fever episode. If your medical history shows that you are not taking any medication with side effects that include hair loss, and if a blood test shows no abnormal thyroid levels or nutrient deficiencies, the feverish flu you had a few weeks ago will remain as the probable cause.
Since the hair follicles are not damaged, the hair grows back again over time. However, the patience of those affected is put to the test: Due to the simultaneous hair loss and the corresponding synchronized new beginning of the cycle of many follicles, the slow growth of individual hairs (only about 1.25 cm per month) is also clearly reflected in the slow recovery of the hair fullness. Depending on how long you wear your hair, it may take a year or more before the hair loss is replaced in a cosmetically acceptable way. Switching to a shorter haircut shortens the waiting time.
Treatment is actually not necessary. But who would not like to do something for their hair in this situation? If the iron level is low, the dermatologist will probably recommend supplementation with iron; other supplements may be considered. However, nobody can guarantee that these efforts will significantly accelerate your hair growth.
Diffuse hair loss due to nutrient deficiency
Diffuse hair loss, but also alopecia areata and androgenetic alopecia are often associated with nutrient deficiency. But: Pronounced nutrient deficiency is much rarer in Western countries than media coverage would suggest. And whether mild nutrient deficiencies – such as the iron deficiency widespread among women, the occasional vitamin D deficiency in the winter season or the slight protein deficiency in some vegans – are actually as problematic as often portrayed in the media is in truth quite unclear .
Our knowledge about the nutrients that are particularly important for hair growth comes from observations in cases of severe deficiencies, which can only occur in cases of long-term significant malnutrition due to poverty and/or extreme ignorance, eating disorders, serious physical diseases, congenital genetic defects or artificial nutrition (intravenous or with a tube). For the typical Central European or American these situations are not relevant at all. The fact that a serious lack of selenium, copper, iron or essential amino acids leads to disturbances in hair growth does not automatically mean that supplementation with these nutrients must necessarily have a good effect in the absence of a deficiency.
Rigorous evidence that a minor deficiency or a borderline, still acceptable status of a certain nutrient is the cause of hair loss is not so easy to provide. Even if hair loss and, for example, mild iron deficiency come together, this is not proof of a causal relationship – iron deficiency (in the sense of falling below the blood concentrations currently defined as optimal) is common, and not everyone affected by it suffers from hair loss (or any symptoms at all).
Manufacturers of dietary supplements advertise the numerous positive effects – also on hair growth – that their products can have. (Or could…) Unlike manufacturers of medicines, however, they do not have to provide any proof for their promises. In this sense, the market for dietary supplements is not state-regulated. In a way, this is also a piece of appreciable freedom: If you think a certain vitamin or mineral would do you good, you can simply buy a corresponding dietary supplement – regardless of the opinion of the professional authorities.
However, the actual scientific evidence for the relationship between hair growth and nutrients in non-deficiency situations is very inadequate. The fact that dermatologists nevertheless often recommend such preparations is partly due to the expectations of patients: The advice to simply wait for three months to see if the symptoms do not improve of their own accord is something that very few doctors like to hear.
Many nutrients or dietary supplements have at least one good thing: they cannot harm you – even if you take significantly more than the generally recommended daily amounts of them. Unfortunately, this does not apply to all of them either: In the meantime, there are several reports in medical literature about poisoning with selenium  or vitamins   – caused by self-medication with dietary supplements. (However, this is still not a common scenario.) Nevertheless, the following applies: According to current knowledge, the effect of most nutrients on the organism can be described with a U-shaped curve. Too much can be just as bad as too little .
In the following we summarize the available information on the most important nutrients typically mentioned in connection with hair loss.
For decades, numerous scientific studies have been investigating whether there is a connection between a slight iron deficiency and hair loss – without being able to give a clear answer to this question.
For example, a European study from 2007 determined the iron status of 5110 women, 9% of whom reported suffering from severe chronic hair loss. Of these 9%, 59% had an iron deficiency – but 48% of women without hair loss problems did not have enough iron in their blood. The study interprets this as an indication of a slightly increased risk of hair loss due to iron deficiency – even if the figures can be read with some justification as proof that hair loss can occur with or without iron deficiency  This is exactly the conclusion reached by several other studies.  In short: The question whether iron deficiency – beyond pronounced deficiency states with clear physical symptoms (iron deficiency anaemia) – increases the risk of hair loss has still not been decided.  However, the available data at least allow the statement that iron deficiency can certainly not be a decisive factor.
Iron is one of the most frequently prescribed supplements for women. Men, on the other hand, are not prone to iron deficiency. The benefit of iron supplementation is limited to deficiencies, an excess supply of iron is not absorbed from the intestine into the blood, and too much iron is even a problem for the body. If the regulatory mechanisms of iron absorption are disturbed, unnecessary iron supplementation can lead to an excess of iron (haemochromatosis). Those affected suffer from a complex of symptoms, including cardiac arrhythmia, liver damage, skin changes, diabetes, joint inflammation and psychological symptoms. Experts therefore recommend that men who eat meat in particular should avoid uncritical iron supplementation.
A real zinc deficiency is rare in western countries – even if this is often read somewhat differently when zinc is the subject of media attention. Even a diet that is unhealthy by other standards usually still contains sufficient zinc. The mineral is contained in meat and eggs, but also in various vegetables and cereals in such sufficient quantities that neither vegetable grouches nor vegans have to fear zinc deficiency.
Real zinc deficiency (e.g. due to congenital or disease-related disorders of zinc absorption by the body) actually causes hair loss and a number of other obvious skin symptoms. If the deficiency is remedied, the hair will also feel better  Only – as already mentioned – the vast majority of people in developed countries do not suffer from zinc deficiency.
Nevertheless, dermatologists very often prescribe zinc supplementation for hair loss. This is not so much to compensate for an assumed deficiency as to have an additional beneficial effect on the health of the hair follicles. Such a positive effect is quite conceivable, but there is no scientific evidence in the form of studies.
Selenium is an essential trace mineral that plays a role in the thyroid gland and in the development of hair follicles, among other things. A pronounced selenium deficiency can therefore have a direct or indirect effect on hair growth (via the hormonal consequences of thyroid dysfunction). However, such a pronounced deficiency occurs almost only in countries with particularly low selenium-rich agricultural soils and, at least currently, does not play a major role beyond the so-called selenium deficiency belt in southwest China. In Central Europe, selenium deficiency is rarely and predominantly associated with rare disorders of selenium uptake, severe diseases and very unbalanced nutrition in eating disorders, alcoholism or artificial nutrition. There are only isolated case reports in the literature, but no systematic studies on the question of the extent to which low selenium levels at the selenium deficiency borderline play a role in hair loss or whether hair loss can be reversed by selenium supplementation.
Despite the obvious lack of research on the subject, selenium is contained in many supplements that are supposed to improve hair growth. This is not only surprising, but even a little worrying: there are actually more reports of selenium poisoning in the scientific literature (with dietary supplements – an incorrectly formulated supplement caused a large case series of selenium poisoning in the USA in 2008 , or through increased consumption of selenium-rich Brazil nuts ) than reports of positive effects of selenium supplements on alopecia. The irony is that selenium poisoning leads to massive hair loss, among other things.
Biotin (vitamin B7)
Biotin – vitamin B7 – is considered the beauty vitamin for hair and skin. It is still unclear what influence biotin, which among other things is involved as a coenzyme in the breakdown of amino acids, actually plays for the hair follicles and the hair protein keratin. What is clear, however, is that a pronounced biotin deficiency in the body does indeed lead to dull, brittle hair; hair loss and brittle nails. These symptoms are typically accompanied by a scaly red rash around the eyes, nose and mouth. A real biotin deficiency can be compensated for by biotin supplementation; this also makes the hair problems disappear.
But: True biotin deficiency is extremely rare (if you eat raw eggs every day, you should be worried: raw egg white contains a substance that binds biotin in the intestine and prevents it from being absorbed into the blood; intestinal diseases and epilepsy medication can also cause a deficiency). To date, not a single scientific study has supported an additional biotin dose at normal biotin levels (although there are hardly any such studies). Reports on the effects of biotin on hair growth have therefore so far been considered purely anecdotal.
In the 1980s, biotin was routinely recommended by dermatologists for hair problems. Without sufficient evidence, as experts emphasize today. Currently the value of the very widespread biotin supplementation is strongly doubted, positive effects in case of hair loss are hardly to be expected with a normal biotin status  However, there is just as little danger from supplementation: As a water-soluble vitamin, excess biotin is simply excreted with the urine. Even if you sometimes read it differently in the media: Biotin overdoses are not described in the specialist literature.  The worst thing that can happen with biotin supplementation at up to three hundred times the recommended daily amount is that the vitamin affects the accuracy of biochemical laboratory tests of blood values (especially described for thyroid hormones ).
Niacin (vitamin B3)
Niacin – vitamin B3 – is also frequently associated with hair growth. The vitamin is of universal importance in the anabolic as well as the degrading (energy) metabolism. The perception of niacin as a skin vitamin stems from the clinical picture of the vitamin deficiency disease pellagra (no longer to be feared in developed countries), which causes, among other things, conspicuous skin changes.
Niacin is contained in many combination preparations which are supposed to be effective against diffuse hair loss and for beautiful hair. There are no scientific studies on whether this makes sense .
Vitamin A is a special case: Although it is not uncommon to find it in supplements for skin and hair, in fact nothing is known in the literature about a connection between vitamin A deficiency and hair loss.
In contrast, hair loss is one of the known symptoms of vitamin A hypervitaminosis, a poisoning with vitamin A. Acute and chronic vitamin A poisoning from supplements is described quite frequently in the specialist literature, as for this vitamin the recommended daily intake and the potentially already toxic intake are very close together (risky doses are only three times higher than the recommended daily requirement!)  A warning must therefore be given against self-medication with vitamin A supplements without a documented vitamin A deficiency.
The members of the vitamin E family are powerful antioxidants. Vitamin E deficiency is rare, but the vitamin is often supplemented by self-medication, often without a detected deficiency, in the hope of preventing inflammation and ageing processes. Particularly in the case of skin diseases, vitamin E (orally as a supplement or locally in the form of ointments etc.) is also part of the standard treatment repertoire of dermatology – although here too without really convincing support from scientific studies .
There is only one specialist publication on the question of whether increased vitamin E intake can have a positive effect on hair loss. In a small study from Malaysia published in 2010, 21 volunteers with hair loss after eight months of supplementation with 100 milligrams of a vitamin E preparation every day were able to enjoy an average of 34.5% more hair, while the control group had 0.5% less hair than at the beginning of the study.  Why these encouraging results were not followed by further investigations, we cannot tell you.
However, like the other fat-soluble vitamins, vitamin E can also be overdosed – although the risk is less high than for vitamin A, as desirable and problematic doses are much further apart (> factor 50). Among other things, vitamin E hypervitaminosis reduces the blood’s ability to clot, and can therefore lead to internal bleeding. A very large study has also indicated that supplementation with 400 IU vitamin E daily (a common dose of vitamin E that is about 20 times the recommended minimum daily intake) could increase the risk of developing prostate cancer .
Amino acids / protein
Amino acids are the building blocks from which all proteins are built. Connective tissue, muscles, hair and nails consist of proteins. In addition, proteins are indispensable for the metabolism simply because all enzymes are proteins. Many amino acids can be synthesized by the body itself – either from their basic building blocks or by converting other amino acids – but there is also a whole range of essential amino acids on whose sufficient supply with food we depend.
The hair protein keratin contains a relatively high proportion of essential amino acids. A diet that does not cover the amino acid requirements of the body therefore naturally has an effect on hair growth. However, medical experience in this respect has been made with patients who have been in severe deficiency states, whether due to poverty, an eating disorder or serious illness. Doctors today agree that an amino acid deficiency does not occur with a normal (and not even necessarily particularly conscious) diet in Western countries. Only vegans, who do not pay attention to sufficient intake of as diverse plant proteins as possible (legumes, nuts, whole grains), are in danger of developing a deficiency.
The amino acid L-lysine represents all essential amino acids with good reason: it is the rarest. Vegans who consciously choose foods rich in L-lysine automatically get enough of the other essential protein components. A lot of L-lysine is contained in soy, seitan, lentils, black beans, quinoa and pumpkin seeds.
Even if there is no deficiency, an additional supplementation with amino acids or protein is often recommended. Whether this is sensible and promising has hardly been researched. There are only a few studies relevant to the topic that have been financed by the manufacturer of a protein-containing combination preparation to promote hair growth (Viviscal).
Polyunsaturated fatty acids
The essential polyunsaturated fatty acids (omega-6 and omega-3 fatty acids) are currently one of the “favourite kids” of the dietary supplement industry. They are needed by the body, among other things, as building blocks of cell membranes and as basic substances for the production of prostaglandins. Prostaglandins are universal messenger substances produced by the body, which regulate inflammatory processes and are also involved in the control of the hair follicle cycle. In addition, fatty acids from vegetable sources and especially from fish oil are said to have positive effects on the blood lipid level, heart and circulation as well as the immune system – although studies have been rather mixed.
The symptoms of severe omega fatty acid deficiencies (which are only observed under non-everyday conditions, such as artificial nutrition or disorders in the absorption of these substances) include hair loss. Conversely, the conclusion that an overabundant supply of essential fatty acids could help against hair loss of other causes is, as with all other nutrients, not compelling and requires careful investigation.
It is known from laboratory studies that some polyunsaturated fatty acids have a similar effect to the hair loss drug finasteride: they inhibit the enzyme 5α reductase, which converts testosterone into dihydrotestosterone and is considered the main cause of androgenetic hair loss)  Together with the role that essential fatty acids play as the starting material for prostaglandin synthesis, this gives two starting points for a possible mechanism of action. As always, one should beware of simplifications: Whether a supplementation actually works as one imagines it to and is free of negative effects can only be determined in large application studies. This is hardly possible for polyunsaturated fatty acids, as for most other nutrients.
There is only one study on the effect of a combined preparation with omega-3 and omega-6 fatty acids (the product contains fish oil, blackcurrant seed oil, vitamins A, C and the antioxidant lycopene), which was financed by the manufacturer of the preparation. Six-month application resulted in 79 women suffering from incipient female androgenetic alopecia, an increase in hair density, a decrease in the proportion of telogen hair and a subjective improvement in diffuse hair loss symptoms .
A single, commercially motivated study is not sufficient proof of the effectiveness of essential fatty acid supplementation in hair loss. Therefore, the evidence in favour of supplementation has to be considered as insufficient in strict terms.
Usually the compensation of a diagnosed nutrient deficiency is easy to achieve (usually by supplementation with a suitable food supplement, sometimes also by injections) – and if this also makes an existing hair problem disappear: all the better.
For this reason, some dermatologists prescribe iron, zinc and/or biotin for alopecia and effluvium even without prior diagnosis: it is a simple measure that may help. However, given the generally good nutritional status of Central Europeans, the probability of success with this alone is not very high. If the cure were so simple, problems with hair loss would hardly be so widespread and persistent
It is potentially a little more problematic if supplementation is done by self-medication. This can lead to interactions with the medication taken, and with some nutrients it is possible to do too much of a good thing. These include iron, selenium and vitamins A and E (see the individual sections for details). The fact that food supplements are freely available should not hide the fact that you can harm yourself through uncritical supplementation. You should therefore always consult your family doctor or dermatologist and stick to the recommended dosages!
However, there is no need to overdramatize the vitamin pills – negative effects of taking nutrient preparations are rare. Nevertheless, the intake of vitamins and minerals without a deficiency is usually regarded by neutral experts as superfluous and relatively critical  However, if unnecessary spending of money is not a problem for you, experimenting with supplements (with medical supervision!) is largely harmless and, who knows, in your particular case may even be beneficial. If you do not have the money: Do not worry, a healthy and varied diet is considered by most experts to be the better strategy anyway.