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 used in connection with the following conditions (refer to the individual health concern for complete information):
| Science Ratings | 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.1 One report exists of vitiligo appearing after ingestion of large amounts of PABA2 and use of amounts over 20 grams per day in small children has resulted in deaths.3 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.4
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.
1. Kantor GR, Ratz JL. Liver toxicity from potassium para-aminobenzoate. J Am Acad Dermatol 1985;13:671–2.
2. Hughes CG. Oral PABA and vitiligo. J Am Acad Dermatol 1983;9:770 [letter].
3. Worobec S, LaChine A. Dangers of orally administered para-aminobenzoic acid. JAMA 1984;251:2348.
4. 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.