What is vitamin B10？

Para-aminobenzoic acid (PABA), or vitamin B10, is an organic compound found in certain foods and produced by the chemical industry. It was once added to sunscreen and has been used as a supplement to help darken gray hair and improve certain skin issues, among other uses.

Vitamin B10 (or vitamin Bx) is an alternative name for the organic compound PABA, a white crystalline substance. It is considered part of the vitamin B complex, although it is not a vitamin nor an essential nutrient. It’s found in brewer’s yeast, organ meat, mushrooms, whole grains, and spinach.

What are the effects of vitamin B10?

Your body can also synthesize the compound using certain bacteria in your gut. PABA then assists in the production of folate (vitamin B9). However, the amount of folate produced is inadequate to meet your needs, so you need to obtain it from other dietary sources. PABA is thought to benefit skin and hair when taken as a supplement. It is industrially produced and sold in pill, powder, extract, and topical application form.

Sun protection

PABA can absorb ultraviolet (UV) rays — especially UVB rays- associated with sunburns and DNA damage. It was thus a key ingredient in sunscreen starting in the 1940s but later linked to allergic skin reactions in some people. Since 2019, PABA is no longer generally recognized as safe and effective for use in sunscreen by the Food and Drug Administration (FDA). It’s sometimes found in certain lotions and other products marketed as moisturizers, often in combination with aloe vera, and it’s rarely used in shampoos, conditioners, and lipsticks.

Skin-related disorders

Besides protecting against UV rays, PABA is claimed to help with skin issues related to hardening, tissue buildup, and discoloration — although how the compound may improve these conditions remains unclear. For one, PABA has been investigated for its use in the treatment of Peyronie’s disease, which is characterized by the buildup of fibrous plaque inside the penis. However, further research is required to determine whether the compound actually works.

PABA has also been identified as a possible treatment for scleroderma, an autoimmune disease that causes skin hardening and fibrous organ deposits. One retrospective study in 467 people with scleroderma found that 90% of those who received potassium PABA supplements experienced mild, moderate, or marked skin-softening, compared with 20% of a control group.

Even so, this is one of the only studies on the topic, and it was conducted over 30 years ago. Other research has suggested that PABA does not affect skin hardening associated with scleroderma, so additional research is needed.

Hair care

One of the earliest uses of PABA supplements was to help with the repigmentation of prematurely gray hair. It has still used for this purpose today, and many personal testimonies suggest it is effective despite a lack of research. Studies in the 1940s and ’50s found that taking PABA at daily doses ranging from 200 mg to 24 grams led to hair darkening and helped gray hair return to its original color.

It’s important to note that some research found that hair became gray again after participants discontinued the supplement. Even though PABA was shown to darken gray hair in early studies, this effect has not been studied recently. Some researchers concluded that PABA should not be taken solely for darkening hair due to its unknown side effects.