PABA is a substance that occurs naturally in our intestines and can also be obtained from food sources and nutritional supplements. It was once considered to be a B vitamin, but is now considered a nonessential nutrient. The full name of PABA is para-aminobenzoic acid. This is also known as ABA, Acide 4-aminobenzoïque, Acide Aminobenzoïque, Acide p-aminobenzoïque, Acide Para-Amino-Benzoïque, Acide Paraaminobenzoïque, Acide Para-Aminobenzoïque, Acido Para Aminobenzoico,Aminobenzoate Potassium, Aminobenzoic Acid, Bacterial Vitamin H1, Ethyl Dihydroxypropyl Aminobenzoate,Glyceryl Paraaminobenzoate, Octyl Diemthyl PABA, P-Aminobenzoic Acid, PABA, Padamate O, Para-Aminobenzoate,Vitamin B10, Vitamin Bx, Vitamin H1, Vitamine B10, Vitamine Bactérienne H1, Vitamine Bx.
Most Common Uses:
People use PABA commonly for vitiligo, pemphigus, dermatomyositis, morphea, scleroderma, and Peyronie’s disease. PABA is also used orally to treat female infertility, arthritis, anemia, rheumatic fever, constipation, disseminated systemic lupus erythematosus, lymphoblastoma cutis, and headaches. It is also used orally to darken gray hair, prevent hair loss, rejuvenate the skin, and prevent phototoxic reactions. Topically, PABA is used as a sunscreen.
PABA is known to be most likely effective when used as a treatment for sunburn as it is an FDA-approved sunscreen. It remains effective in protecting the skin against the UV rays even during sweating, but not when the skin is immersed in water. It can act as a filter to block the penetration of ultraviolet (UV) radiation to the cells of the epidermis. PABA primarily blocks UVB sunlight, but may give some protection against UVA radiation at higher concentration.
On the other hand, PABA is known to be less effective, or have insufficient evidence pertaining to its efficacy on scleroderma, dermatomyositis, morphea, pemphigus, Peyronie’s disease and vitiligo.
Possible Adverse Reactions:
Orally, nausea, vomiting, dyspepsia, diarrhea, and anorexia are the most common side effects of PABA. PABA should be discontinued if adverse effects prevent the patient from eating. In one report up to 25% of patients discontinued PABA due to intolerance of side effects. Allergic reactions including fever and skin rash have also occurred. Liver toxicity, including fatal hepatitis has been reported in patients taking high doses (12-48 grams per day). In one case 12 grams per day for 2 months caused liver toxicity. Although PABA is sometimes used to treat vitiligo, it has also been reported to cause vitiligo. High dose PABA (up to 48 grams per day) can cause decreased white blood count below 4000 mm3 in approximately 30% of patients. Death has been reported in 3 children treated with 24 grams of PABA per day for rheumatic fever or arthritis. At autopsy, all had fatty changes in the liver, kidney, and myocardium. Topically, PABA can cause contact dermatitis and sometimes paradoxical photosensitivity (272). Some forms of PABA may stain clothing with a yellow discoloration.