Folic Acid, Folate and Hair Loss: What the Evidence Shows
Last reviewed on 19 July 2026. We review our treatment guides every six months to keep them accurate.
Folic acid is one of the most searched supplements for hair, and the honest answer is narrower than the marketing. Folate, the vitamin that folic acid supplies, is genuinely needed for the rapid cell division that builds a hair, so if you are short of it that shortfall is worth correcting. What has not been shown is that taking extra folic acid grows hair in someone whose folate levels are already normal. Folate deficiency also turns out to be uncommon, even among people who go to a doctor specifically about hair shedding.
For a plain, independently maintained account of what folate does, how much you need and what happens if you take too much, the NHS pages on B vitamins and folic acid are the best starting point, alongside the NHS page on folic acid as a medicine. Hair loss has many causes, so please treat this page as general information and speak to a GP or a pharmacist about your own situation before starting any supplement.
The idea to hold on to is the same one that runs through our guide to hair gummies. Correcting a genuine deficiency can improve hair, because the shortfall was holding it back. Adding more of a nutrient once you already have enough does not push growth higher. Folate dissolves in water and is not stored in the body for long, so a surplus is largely passed out rather than turned into extra hair.
What folic acid and folate actually are
Folate is a B vitamin found naturally in food, also known as vitamin B9. Folic acid is the manmade version of it, the form used in supplements and in fortified foods. The two are often used interchangeably in conversation, but the distinction matters when you get to doses and to safety, because the synthetic form is absorbed more efficiently and is what ends up in a tablet.
The body uses folate to make healthy red blood cells and, in pregnancy, to reduce the risk of neural tube defects such as spina bifida. Underneath both of those jobs sits the same piece of biochemistry: folate is required to build the DNA that a cell needs before it can divide. That is why a shortage shows up first in tissues that divide fastest, and it is the reason folic acid gets talked about in connection with hair at all.
Why hair is a plausible place to look
A growing hair follicle is one of the most metabolically demanding structures in the body. The cells in the hair bulb divide faster than almost any other healthy tissue, which is why chemotherapy, which targets rapidly dividing cells, causes hair loss. On paper, then, a vitamin that the body needs in order to divide cells at all is something hair should be sensitive to.
That is a plausible mechanism, and it is worth understanding, but a plausible mechanism is not a demonstrated effect. The question that matters is not whether hair follicles use folate, because every cell in the body does. It is whether people who are already getting enough grow more hair by taking more, and whether people who are short of it lose hair because of that shortfall. Those are empirical questions, and the studies that address them are set out further down.
Where folate comes from in a UK diet
Good sources of folate include broccoli, brussels sprouts, leafy green vegetables such as cabbage, kale, spring greens and spinach, peas, chickpeas and kidney beans, and breakfast cereals that have been fortified with folic acid. The body holds no long-term store, so it needs topping up regularly through food. The NHS estimates the body's folate reserve lasts around four months.
One piece of context has changed recently and is often reported inaccurately. The UK legislated in November 2024 to make folic acid fortification of non-wholemeal common wheat flour compulsory, at 0.25mg per 100g, but that requirement only applies from 13 December 2026. At the time of this review it has not yet taken effect, so unlike in the United States, folic acid is not yet routinely added to standard UK white flour. Some breakfast cereals and breads are voluntarily fortified in the meantime.
Does folic acid help hair growth? What the evidence shows
Graded honestly, the evidence sits low on the scale. Almost all of it is observational: researchers measure folate levels in a group of people with a hair problem and compare them with a group without one. That design can reveal an association, but it cannot show that one thing caused the other, and it certainly cannot tell you what would happen if you took a supplement. There is no randomised, placebo-controlled trial of folic acid on its own for hair growth in people who are not deficient. The most widely cited review of vitamins and minerals in hair loss ends by calling for exactly that kind of trial, which is a polite way of saying it does not yet exist.
Within that limitation, here is what has actually been found. In alopecia areata, an autoimmune condition causing patchy hair loss, the results conflict. One study compared 43 people with the condition against 36 healthy controls and found no significant difference in serum folate or vitamin B12. Another, in 29 people whose alopecia areata affected more than a fifth of the scalp, found that folate measured inside the red blood cells was significantly lower than in controls, and lower still in those with total scalp or whole-body hair loss, yet found no difference in the folate or B12 measured in the blood serum. Two measures, two different answers, which is itself a warning against reading too much into any single study.
In telogen effluvium, the diffuse shedding that follows illness, stress, childbirth or rapid weight loss, the picture is clearer and less flattering to folic acid. A review of 115 patients found none who were folate deficient. A 2023 study of 973 patients found folate deficiency in 2.5 per cent of those tested and, in the subgroup who had their hair formally measured, no relationship at all between folate level and the proportion of hairs actively growing. A 2025 review of 2,851 women with telogen effluvium found folic acid deficiency in just eight of them, 0.6 per cent, against low ferritin in 46.5 per cent. In other words, among thousands of women who went to a clinic because their hair was falling out, folate was almost never the problem and low iron very often was.
A separate study of 91 people with diffuse hair loss found no significant difference in serum folate compared with controls, and one report of 200 women with chronic telogen effluvium found that 28.5 per cent had folate levels that were higher than normal rather than lower, though it did not publish its methods, so little can be concluded from it. Summing up the field, a 2017 dermatology review put it bluntly: folate deficiency mainly causes megaloblastic anaemia, without hair loss as a feature.
The one hair-related finding that recurs is about colour rather than quantity. A case-control study of 52 Indian people under 20 with premature greying found lower levels of vitamin B12 and folic acid than in matched controls. That is a small study, in one population, about greying rather than hair loss, and it shows an association only. It does not establish that folic acid restores pigment, and no trial has shown that it does.
What about folic acid hair growth before and after pictures?
This is the single most common thing people search for on this subject, so it deserves a straight answer. The before and after pictures circulating on social media and on supplement websites are testimonials, not evidence. There is no comparison group, so nobody knows what that person's hair would have done without the folic acid. There is no blinding, and the person holding the camera very much wants the product to have worked. The lighting, the styling, the parting, the wet or dry state of the hair and the angle all change how dense hair looks, and the second photograph is almost always the more flattering one.
Timing is the bigger problem. Hair grows in cycles, and the most common cause of sudden diffuse shedding, telogen effluvium, usually gets completely better without any treatment. The shedding phase typically runs three to six months, after which new hair starts to grow, with several more months before the hair looks normal again. People also tend to start a supplement at the point their hair looks worst, which is statistically the point from which it is most likely to improve anyway. Anything started at that moment will appear to have worked.
None of that means every before and after is fake. Some show a real improvement. The honest reading is that where hair genuinely got better, the likeliest explanations are that a recovering telogen effluvium ran its course, or that a real deficiency was corrected at around the same time. If someone was genuinely short of folate, or of iron, or had an untreated thyroid problem, and that was put right, better hair can follow. That is a good reason to get tested. It is not a reason to expect the same result if your levels are already normal, which is the situation most people are in.
Folate deficiency: who is at risk and how you find out
Because the body keeps only about four months of folate in reserve, a deficiency can develop reasonably quickly if intake drops or absorption fails. The NHS lists the main causes as a generally poor or restrictive diet, regular heavy drinking, and conditions that stop the gut absorbing folate properly, such as coeliac disease and Crohn's disease. Folate can also be lost through the kidneys in congestive heart failure, in liver damage caused by heavy drinking, and during long-term dialysis. Several medicines reduce folate or make it harder to absorb, including some epilepsy medicines, colestyramine, sulfasalazine and methotrexate. Pregnancy, cancer, blood disorders such as sickle cell disease and any illness causing sustained inflammation all raise the body's demand for it.
It is worth being clear about what a folate deficiency actually feels like, because the old version of this page, along with much of the internet, gets it wrong. The NHS symptom list is extreme tiredness, a lack of energy, pins and needles, a sore and red tongue, mouth ulcers, muscle weakness, problems with vision, and psychological effects ranging from low mood or anxiety to confusion and problems with memory and judgement. Hair loss is not on that list, and grey hair is not either. Both are commonly repeated online, and neither is a recognised feature of folate deficiency.
The way to find out is a blood test through your GP, not a symptom checklist and not a guess based on your hairbrush. The American Academy of Dermatology gives the same advice for supplements generally: before taking anything to grow your hair, find out whether you are actually short of it, because a blood test can tell you and a mirror cannot. If you are shedding, it is worth asking about a full blood count, ferritin and thyroid function as well, since those are the findings that actually come up.
How much folic acid a day? The UK figures
These are national dietary recommendations rather than advice for any individual, and none of them is a hair-growth dose. Adults in the UK need 200 micrograms of folate a day, and the NHS position is that most people should get that from a varied and balanced diet without supplementing at all. Anyone who is pregnant, trying for a baby or could become pregnant is advised to take a 400 microgram folic acid supplement daily until they are 12 weeks pregnant, to reduce the risk of neural tube defects.
A 5mg tablet is a different thing altogether. That is a prescription-strength dose, used for specific medical reasons: women at increased risk of a pregnancy affected by a neural tube defect are advised to take 5mg daily until 12 weeks, after speaking to a doctor first, and 5mg is also used to treat folate deficiency anaemia and to reduce the side effects of methotrexate. It is not a hair supplement, and it is five times the 1mg a day that the NHS describes as the level below which an ordinary folic acid supplement is unlikely to cause harm. If you have been prescribed 5mg, there is a medical reason for it, and it is worth understanding what that reason is rather than treating it as a beauty product.
Folic acid is a medicine as well as a supplement, and the usual cautions apply. The NHS notes it may not be suitable if you have vitamin B12 deficiency anaemia or pernicious anaemia, a coronary stent, or cancer, and that it can interact with some epilepsy medicines, with chloramphenicol and co-trimoxazole, with sulfasalazine, with lithium and with aspirin. It also advises avoiding or limiting alcohol, because alcohol can affect how well folic acid works. Any question about whether to take it, and at what dose, belongs with a GP or a pharmacist rather than an article.
The safety point that matters most: masking a B12 deficiency
If you take one thing from this page, take this one. The NHS is explicit that folic acid doses above 1mg a day can mask the symptoms of a vitamin B12 deficiency, which can eventually damage the nervous system if it is not spotted and treated.
The reason is worth understanding. A B12 deficiency and a folate deficiency both produce the same kind of anaemia, in which the body makes abnormally large red blood cells. That anaemia is often the visible sign that sends someone to a doctor. Folic acid can correct the blood picture on its own, so the anaemia improves and the alarm goes quiet, while the underlying B12 problem carries on untreated. B12 deficiency also damages nerves, and unlike the anaemia, some of that nervous-system damage can be permanent if it is left too long. The risk is greatest in older people, because absorbing B12 becomes harder with age.
In practice this means two things. If you have symptoms that could point to either deficiency, ask for both folate and B12 to be tested rather than starting folic acid on spec. And tell any doctor treating you what supplements you are taking, because a folic acid habit bought for your hair can quietly change how a blood result reads.
What does have evidence for hair loss
For pattern hair loss, the treatments with a genuine evidence base are minoxidil, applied to the scalp, and, for men, finasteride, a prescription tablet. Neither is a cure, both work only for as long as they are used, and finasteride is a decision to make with a doctor because of its side-effect profile and because it is not suitable for women. For sudden diffuse shedding, the useful step is finding the cause, which is why a full blood count, ferritin and thyroid tests are the first things a clinician tends to order. None of this makes folic acid harmful. It simply puts it in perspective: it is a vitamin your body needs, not a treatment for hair loss.
If you are having a hair transplant or any other surgery, tell your surgeon and your clinic about every supplement and medicine you take, folic acid included, and follow the pre-operative instructions they give you. Clinics differ in what they ask patients to stop and when, so the safe course is to disclose it and follow your own clinic's guidance rather than a general rule from an article. If folic acid has been prescribed to you, for a pregnancy or alongside a medicine such as methotrexate, do not stop it on your own account: ask the person who prescribed it.
The bottom line
Folate matters. Your body cannot build new cells without it, and a real deficiency is worth finding and correcting, both for your general health and because feeling exhausted and unwell is rarely good for your hair. What the evidence does not support is the step the marketing takes next: that swallowing more folic acid than you need will grow hair. The studies that have looked found folate deficiency to be rare among people with hair loss, no relationship between folate levels and hair actively growing, and no trial testing whether supplementing helps people who are not deficient. If your hair is thinning or shedding, the most useful thing you can do is see a GP or a dermatologist, get tested rather than guess, and put your money towards whatever the tests actually turn up.
Frequently asked questions
Does folic acid make your hair grow?
There is no good evidence that it does in someone whose folate levels are already normal. Folate is needed for the cell division that builds a hair, so a genuine deficiency is worth correcting, but no randomised, placebo-controlled trial has shown that extra folic acid grows hair in people who are not deficient. Studies of people with hair shedding have repeatedly found folate deficiency to be uncommon and have found no relationship between folate levels and the proportion of hair actively growing.
What about folic acid hair growth before and after pictures?
Those pictures are testimonials rather than evidence. There is no comparison group, no blinding and no control over lighting, styling or camera angle, all of which change how dense hair looks. Timing also confounds them, because telogen effluvium usually recovers on its own over several months and people tend to start a supplement when their hair is at its worst. Where a genuine improvement has happened, the likeliest explanations are a shedding phase running its course or a real deficiency, often iron rather than folate, being corrected at the same time.
How much folic acid should I take a day?
That is a question for a GP or pharmacist rather than an article, because it depends on why you are taking it. For context, the NHS says UK adults need 200 micrograms of folate a day and that most people get this from a varied diet without supplementing. Anyone pregnant, trying for a baby or who could become pregnant is advised to take 400 micrograms of folic acid daily until 12 weeks pregnant. The NHS describes 1mg a day or less as the level at which an ordinary folic acid supplement is unlikely to cause harm. None of these is a dose for hair.
Can folic acid hide a B12 deficiency?
Yes, and this is the most important safety point on the page. Folic acid taken above 1mg a day can mask the symptoms of a vitamin B12 deficiency. Both deficiencies cause the same type of anaemia, and folic acid can correct that anaemia while the B12 problem continues untreated underneath. B12 deficiency also damages nerves, and some of that damage can be permanent if it is not caught. Older people are most at risk, because B12 becomes harder to absorb with age. If you suspect either deficiency, ask for both to be tested rather than starting folic acid on your own.
Is 5mg folic acid safe for hair?
5mg is a prescription-strength dose given for specific medical reasons, such as a pregnancy at higher risk of neural tube defects, treating folate deficiency anaemia, or reducing the side effects of methotrexate. It is not a hair supplement and should not be taken as one. It is well above the 1mg a day the NHS describes as unlikely to cause harm in an ordinary supplement, and above the threshold at which folic acid can mask a B12 deficiency. If you have been prescribed 5mg, keep taking it as directed and ask your prescriber any questions about it.
Can a folate deficiency cause hair loss?
Hair loss is not a recognised feature of folate deficiency, and it does not appear on the NHS symptom list, which covers extreme tiredness, pins and needles, a sore red tongue, mouth ulcers, muscle weakness, vision problems and effects on mood and memory. A dermatology review of the subject concluded that folate deficiency mainly causes megaloblastic anaemia without hair loss. Severe anaemia from any cause leaves people exhausted and unwell, and general ill health can trigger shedding, so the two can appear together, but that is not the same as folate deficiency causing hair loss directly.
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