Shop products for PABA 
What is it?
Para-aminobenzoic acid (PABA) is a compound that is an essential nutrient for microorganisms and some animals, but has not been shown to be essential for people. PABA is considered by some to be a member of the vitamin B-complex, though its actions differ widely from other B vitamins.
PABA has been reported to enhance the effects of cortisone.1 It may also prevent or even reverse accumulation of abnormal fibrous tissue.
The most well-known property of PABA is as an effective sunscreen, when used topically. Oral PABA supplementation has not been shown to possess any sunscreening properties.2
An isolated trial published in 1942 reported that 12 of 16 infertile women were able to become pregnant after supplementing with 100 mg of PABA taken four times per day for three to seven months.3 The effect of PABA on fertility has not been studied in modern research.
Researchers have attempted to discover whether large amounts of PABA would be helpful in various connective tissue disorders. Although preliminary studies have reported that PABA (12 grams per day) was helpful to people with scleroderma,4 5 6 a double-blind trial found that supplementation with PABA did not lead to improvement.7
Older published reports of uncontrolled investigations suggest that PABA may be helpful in a variety of conditions, including dermatomyositis,8 Peyronie’s disease (accumulation of abnormal fibrous tissue in the penis),9 pemphigus (a severe blistering disease),10 and vitiligo (a disorder in which patches of skin lose their pigmentation).11 However, PABA was reported to cause vitiligo in one report.12
Older preliminary reports found that PABA darkened grey hair in a minority of elderly (but not younger) people.13 In these trials, between 200 and 600 mg of PABA was taken per day for several months, in some cases accompanied by other B vitamins. However, at least one other study found that PABA did not darken grey hair.14 Therefore, the evidence supporting the use of PABA as a way to return grey hair to its original colour remains very weak.
PABA has been used in connection with the following conditions (refer to the individual health concern for complete information):
| Rating | Health Concerns |
|---|---|
 |
Dermatomyositis Pemphigus Peyronie’s disease Scleroderma |
Reliable and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary
studies suggesting a health benefit or minimal health benefit. For an herb, supported by traditional use but
minimal or no scientific evidence. For a supplement, little scientific support and/or minimal
health benefit. | |
Who is likely to be deficient?
Deficiencies of PABA have not been described in humans, and most nutritionists do not consider it an essential nutrient.
Which form of PABA is best?
PABA is available as a nutritional supplement, but because it is mildly acidic, it can cause stomach irritation when taken in large amounts. The potassium salt of PABA, called Potaba®, which is available by prescription, tends to be better tolerated.
How much is usually taken?
Small amounts of PABA are present in some B-complex vitamins and multivitamin formulas. The amount of PABA used in the studies described above ranged from 300 mg to 12 grams per day. Anyone taking more than 400 mg of PABA per day should consult a physician.
Are there any side effects or interactions?
No serious side effects have been reported with 300–400 mg per day. Larger amounts (such as 8 grams per day or more) may cause low blood sugar, rash, fever, and (on rare occasions) liver damage.15 One report exists of vitiligo appearing after ingestion of large amounts of PABA16 and use of amounts over 20 grams per day in small children has resulted in deaths.17 There is also a report of a death from toxic hepatitis in a person with lupus, who took as much as 48 grams per day for six days, followed by 8 grams per day for seven months.18
No interactions between PABA and other nutrients have been reported. However, PABA interferes with sulfa drugs (a class of antibiotics) and therefore should not be taken when these medications are being used.
Are there any drug
interactions?
Certain medicines may interact with PABA. Refer to drug
interactions for a list of those medicines.
References
1. Wiesel LL, Barritt AS, Stumpe WM. The synergistic action of para-aminobenzoic acid and cortisone in the treatment of rheumatoid arthritis. Am J Med Sci 1951;222:243–8.
2. Willis I, Kligman AM. Aminobenzoic acid and its esters. The quest for more effective sunscreens. Arch Dermatol 1970;102:405–17.
3. Sieve BF. The clinical effects of a new B-complex factor, para-aminobenzoic acid, on pigmentation and fertility. South Med Surg 1942(March);104:135–9.
4. Zarafonetis CJD. The treatment of scleroderma: results of potassium para-aminobenzoate therapy in 104 cases. In: Mills LC, Moyer JH eds. Inflammation and Diseases of Connective Tissue. Philadelphia: W. B. Saunders Co. 1961, 688–96.
5. Zarafonetis CJD, Dabich L, Negri D, et al. Retrospective studies in scleroderma: effect of potassium para-aminobenzoate on survival. J Clin Epidemiol 1988;41:193–205.
6. Zarafonetis CJ, Dabich L, Devol EB, et al. Retrospective studies in scleroderma: pulmonary findings and effect of potassium p-aminobenzoate on vital capacity. Respiration 1989;56:22–33.
7. Clegg DO, Reading JC, Mayes MD, et al. Comparison of aminobenzoate potassium and placebo in the treatment of scleroderma. J Rheumatol 1994;21:105–10.
8. Grace WJ, Kennedy RJ, Formato A. Therapy of scleroderma and dermatomyositis. NY State J Med 1963;63:140–4.
9. Zarafonetis CJD. Treatment of Peyronie’s disease with potassium para-aminobenzoate. J Urol 1959;81:770–2.
10. Zarafonetis CJD, Curtis AC, Shaw JM. Treatment of pemphigus with potassium para-aminobenzoate. Am J Med Sci 1956;231:30–50.
11. Sieve BF. Further investigations in the treatment of vitiligo. Virginia Med Monthly 1945(January):6–17.
12. Hughes CG. Oral PABA and vitiligo. J Am Acad Dermatol 1983;9:770 [letter].
13. Gaby AR. The story of PABA. Nutr Healing 1997;March:3–4, 11 [review].
14. Zarafonetis CJD. Darkening of gray hair during para-amino-benzoic acid therapy. J Invest Dermatol 1950;15:399–401.
15. Kantor GR, Ratz JL. Liver toxicity from potassium para-aminobenzoate. J Am Acad Dermatol 1985;13:671–2.
16. Hughes CG. Oral PABA and vitiligo. J Am Acad Dermatol 1983;9:770 [letter].
17. Worobec S, LaChine A. Dangers of orally administered para-aminobenzoic acid. JAMA 1984;251:2348.
18. Zarafonetis CJD, Grekin RH, Curtis AC, et al. Further studies on the treatment of lupus erythematosus with sodium para-aminobenzoate. J Invest Dermatol 1948;11:359.
