PABA
Useful mainly for adults with Peyronie's disease considering potassium para-aminobenzoate (POTABA) under clinician supervision.
Quick decision guide
May help most
Adults with Peyronie's disease considering potassium para-aminobenzoate (POTABA) under clinician supervision
Common dosing range
25–500 mg/day for supplements; 4–12 g/day for POTABA prescription use in fibrotic disease
When to expect effects
Months (fibrotic conditions); not established for other uses
Watch out for
Antagonizes sulfonamide antibiotics — must not be taken concurrently with sulfamethoxazole, dapsone, or sulfasalazine
What is it
Para-aminobenzoic acid (PABA, 4-aminobenzoic acid) is a benzoic acid derivative bearing an amino group at the para position (C 7 H 7 NO 2 ). It is an intermediate in bacterial, plant, and fungal folate biosynthesis, where it is condensed with pterin to form dihydropteroate; the antifolate sulfonamide antibiotics are structural analogs that competitively block this step. PABA is not a vitamin for humans because we do not synthesize folate and obtain it preformed in our diet; it was historically classified as a B-complex vitamin under the now-obsolete designations 'vitamin Bx' or 'vitamin B10' and remains marketed as a vitamin-like supplement. Topically, PABA was widely used as a UVB-absorbing sunscreen agent until allergic and staining reactions led to its replacement by other UV filters.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
Peyronie's disease (potassium para-aminobenzoate) Limited Evidence | Modest reduction in plaque size and pain in older RCT; small effect | Men with Peyronie's disease, under urologist supervision | Months |
scleroderma and fibrotic skin disorders Mixed Evidence | Not consistently demonstrated | Adults with scleroderma or morphea under specialist care | Months |
Peyronie's disease (potassium para-aminobenzoate)
- Effect
- Modest reduction in plaque size and pain in older RCT; small effect
- Best fit
- Men with Peyronie's disease, under urologist supervision
- Time
- Months
scleroderma and fibrotic skin disorders
- Effect
- Not consistently demonstrated
- Best fit
- Adults with scleroderma or morphea under specialist care
- Time
- Months
Evidence for 2 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
Peyronie's disease (potassium para-aminobenzoate)
Disease adjunctPotassium para-aminobenzoate (POTABA) at 3–12 g/day has been used for Peyronie's disease based on the hypothesis that PABA may reduce fibrosis through modulation of oxidative stress and TGF-beta signaling. One older RCT found modest reduction in plaque size and penile pain. Evidence is limited to small, older studies with methodological limitations. POTABA at therapeutic doses requires medical supervision due to hepatotoxicity risk and GI burden.
Bottom line: Weak but not absent evidence — only consider under urologist supervision; self-dosing at therapeutic levels is not appropriate.
scleroderma and fibrotic skin disorders
Disease adjunctPABA and POTABA have been tried in scleroderma and other fibrosing skin conditions based on the same anti-fibrotic hypothesis as Peyronie's disease. Clinical trial results have been inconsistent and methodologically weak. No modern, adequately powered RCT has established efficacy. This use is largely historical and not part of current rheumatology treatment guidelines.
Bottom line: Not supported by current evidence — this is a historical use without modern clinical backing.
Evidence is mixed
The few available trials are old, small, and of poor quality; results have not been reproduced in contemporary study designs.
How to take it
What to track
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
Hepatic toxicity (rare but documented at high doses, including jaundice and severe hepatitis)
Leukopenia at high doses
Hemolysis in G6PD deficiency
Contact dermatitis and photoallergy with topical use
Who should avoid it
- Anyone on sulfonamide antibiotics (sulfamethoxazole-TMP, dapsone, sulfasalazine) — direct antagonism reduces antibiotic efficacy
- People with renal or hepatic impairment
- People with G6PD deficiency
- Pregnant or breastfeeding women
Pregnancy & breastfeeding
Avoid during pregnancy and breastfeeding — insufficient safety data and potential fetal concern.
Interactions
PABA is a structural analog of sulfonamides and competitively reverses their mechanism — reduces or eliminates antimicrobial efficacy
High-dose PABA may theoretically affect coagulation parameters; monitor if combining
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
References by claim
Track PABA with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.