PABA for Hair Growth: What Does the Evidence Show?
PABA — para-aminobenzoic acid — has a long association with hair supplements, particularly products aimed at premature greying. It is sometimes called “vitamin B10”, although it is not officially recognised as an essential vitamin. So what can PABA realistically do for the hair?
What is PABA?
PABA stands for para-aminobenzoic acid, an organic compound that occurs naturally in small amounts in certain foods and can also be produced by some bacteria.
You may see PABA described online as “vitamin B10”, but this name can be misleading.
PABA is not recognised as an essential vitamin for humans and there is no established daily requirement in the way there is for recognised B vitamins such as folate, niacin or pantothenic acid.
It does, however, have a long history of use in nutritional supplements and older cosmetic formulations.
Some bacteria use PABA as part of their own folate-synthesis pathway, but humans do not rely on PABA supplementation to manufacture folate. Folate itself is an essential human nutrient; PABA is not.
Why did PABA become associated with hair?
Much of PABA's reputation in hair supplements dates back several decades, particularly to early reports involving premature greying.
Older studies and case reports observed darkening of grey hair in some people taking relatively large amounts of PABA.
These findings are interesting historically, but the studies were small, old and do not provide the kind of evidence that would now be required to establish PABA as a reliable treatment for grey hair.
There is even less convincing evidence that PABA directly stimulates new scalp-hair growth or prevents common forms of hair loss.
Does PABA promote hair growth?
PABA is sometimes included in multi-ingredient hair formulas, but there is not strong clinical evidence showing that PABA supplementation reliably increases hair density, stops shedding or regrows hair lost through androgenetic alopecia.
Its place in modern hair supplementation is therefore better understood as a supportive legacy ingredient rather than a proven hair-growth treatment.
Where there is some interest
- Historical research into premature hair greying.
- Longstanding use in multi-ingredient hair supplements.
- Small amounts occur naturally in some foods.
- It has biological relevance in certain microorganisms.
- It can form one component of a wider nutritional formula.
What hasn't been established
- That PABA reliably regrows thinning scalp hair.
- That it blocks DHT.
- That it stops male or female pattern hair loss.
- That it reliably prevents excessive shedding.
- That it repairs weakened hair follicles.
- That it permanently reverses grey hair.
Can PABA reverse grey hair?
This is the claim most closely associated with PABA.
Reports from the mid-20th century suggested that some people taking PABA developed darker hair or partial repigmentation.
But those findings should be interpreted cautiously.
Historical interest does not equal proven treatment.
The old PABA studies were limited by modern research standards, and hair colour frequently returned to grey after supplementation stopped.
There is not enough high-quality evidence to recommend PABA as a reliable treatment for reversing grey hair.
Can PABA prevent hair loss?
PABA is not an established treatment for common forms of hair loss.
It does not have good evidence showing that it prevents androgenetic alopecia, telogen effluvium, postpartum shedding or other major causes of excessive hair fall.
It also should not be described as a DHT blocker.
If someone is experiencing persistent or progressive thinning, the more useful question is what type of hair loss is occurring and what is driving it.
Does PABA work better with MSM or folate?
PABA is sometimes combined with ingredients such as MSM, folate, biotin, choline and other nutrients in multi-ingredient hair supplements.
There is nothing inherently wrong with combining these ingredients, but there is not strong clinical evidence showing that PABA becomes a proven hair-growth treatment simply because it is used alongside them.
Each ingredient has a different nutritional or biological rationale and should be judged on its own evidence.
Which foods contain PABA?
Small amounts of PABA can occur naturally in a variety of foods.
Organ meats
Liver and other organ meats are commonly cited dietary sources of naturally occurring PABA.
Mushrooms
Certain mushrooms can contain small amounts of PABA alongside many other naturally occurring compounds.
Whole grains
Whole grains and cereal-based foods may provide small dietary amounts of PABA.
Spinach & vegetables
Some vegetables, including spinach, are also listed among natural dietary sources.
There is no recognised requirement to target a specific daily PABA intake from food for healthy hair.
Is there a recommended daily dose of PABA?
No official daily nutritional requirement has been established for PABA because it is not recognised as an essential human vitamin.
That means claims such as “500 mg is the recommended daily dose” should not be presented as though they are recognised nutritional guidance.
Historical studies have used widely varying amounts, sometimes at very high doses, but that does not make those doses appropriate for routine supplementation.
Can PABA cause side effects?
Yes. PABA is not automatically harmless simply because it can occur naturally.
High doses should not be taken casually.
Reported adverse effects can include nausea, vomiting, digestive upset, diarrhoea, loss of appetite and skin reactions.
Very high supplemental intakes have also been associated with more serious adverse effects, including liver problems.
PABA can also interact with certain medicines, so concentrated supplementation may not be appropriate for everybody.
What about PABA's other supposed health benefits?
Older sources sometimes claim that PABA can treat conditions ranging from infertility and arthritis to lupus, anaemia and headaches.
These claims should not be repeated as established benefits.
PABA is not a general treatment for those medical conditions, and supplement use should not be confused with evidence-based medical care.
Three claims that need correcting
“PABA is vitamin B10.”
PABA is sometimes given this informal name, but it is not officially recognised as an essential B vitamin in humans.
“PABA reverses grey hair.”
Historical reports found hair darkening in some users, but the evidence is old, limited and not strong enough to consider PABA a reliable grey-hair treatment.
“PABA prevents hair loss when combined with other nutrients.”
PABA may be used within broader formulas, but there is no good clinical evidence that it prevents common forms of hair loss simply because it is paired with MSM, folate or other ingredients.
Why is PABA included in HR23+®?
PABA is included in HR23+ as one component of its broader 23-ingredient nutritional hair-support formula.
Its inclusion reflects its long history of use in hair-focused supplements and its wider botanical and nutritional context.
It is not presented as a stand-alone treatment for hair loss or as a guaranteed way to reverse grey hair.
A supporting ingredient
PABA has a long history of use in hair-focused nutritional formulas, particularly those concerned with hair pigmentation.
Historical rather than proven
Older studies generated interest in PABA and grey hair, but modern evidence remains limited.
Part of a wider formula
HR23+ combines PABA with selected vitamins, minerals and botanical ingredients rather than relying on a single compound.
Support, not treatment
PABA should be viewed as one supporting component within HR23+, not as a proven treatment for alopecia or hair greying.
PABA has an interesting hair history — but the evidence is limited.
PABA has been associated with hair supplements for decades, largely because of early reports involving premature greying.
Those findings remain interesting, but they have not translated into strong modern evidence that PABA reliably restores hair colour or stimulates new hair growth.
It is also not a recognised vitamin, DHT blocker or established treatment for male or female hair loss.
Within HR23+, PABA is best understood as one supporting ingredient within a much broader nutritional formula.
PABA. One part of a 23-ingredient formula.
HR23+® combines PABA with 22 other selected vitamins, minerals and botanical ingredients in one dedicated daily hair-support formula for men and women.
Explore HR23+®PABA and hair growth: FAQ
Is PABA vitamin B10?
PABA is sometimes called vitamin B10, but this is an informal name. It is not officially recognised as an essential human vitamin.
Does PABA make hair grow?
There is limited evidence that PABA directly stimulates scalp-hair growth. It is not an established treatment for thinning hair or androgenetic alopecia.
Can PABA reverse grey hair?
Older studies reported hair darkening in some people taking PABA, but the evidence is limited and outdated. PABA has not been established as a reliable treatment for reversing grey hair.
Does PABA prevent hair loss?
PABA has not been shown to reliably prevent male or female pattern hair loss, telogen effluvium or other common forms of excessive shedding.
Does PABA block DHT?
There is no established evidence that PABA acts as a clinically effective DHT blocker.
Is there a recommended daily dose of PABA?
No official daily nutritional requirement exists for PABA because it is not recognised as an essential vitamin.
Which foods contain PABA?
Small amounts may occur naturally in foods such as organ meats, mushrooms, whole grains and some vegetables.
Why is PABA included in HR23+®?
PABA is included as one supporting component of HR23+'s broader 23-ingredient nutritional hair-support formula. It is not presented as a stand-alone treatment for hair loss or grey hair.
This article is for general information only and should not be considered medical advice. Persistent, sudden, severe or unexplained hair loss should be appropriately assessed. PABA supplements may cause side effects or interact with medicines and are not suitable for everybody.