PABA (Para-aminobenzoic acid)

Para-aminobenzoic acid (PABA) is a chemical found in the folic acid vitamin and also in several foods including grains, eggs, milk, and meat.

PABA is taken by mouth for skin conditions including vitiligo, pemphigus, dermatomyositis, morphea, lymphoblastoma cutis, Peyronie's disease, and scleroderma. PABA is also used to treat infertility in women, arthritis, "tired blood" (anemia), rheumatic fever, constipation, systemic lupus erythematosus (SLE), and headaches. It is also used to darken gray hair, prevent hair loss, make skin look younger, and prevent sunburn.

PABA is best known as a sunscreen that is applied to the skin (used topically).

PABA doesn't seem to be taken by mouth as often as it used to be, possibly because some people question its safety and effectiveness.

How does it work?

PABA is used as a sunscreen because it can block ultraviolet (UV) radiation to the skin.

Sunburn.
Peyronie's disease.
Skin condition called dermatomyositis.
Eye infection caused by herpes virus (herpes keratitis).
Patchy, white skin (lichen sclerosis).
Patchy hardened skin (Morphea).
Skin condition called pemphigus.
Skin condition called vitiligo.
Arthritis.
"Tired blood" (anemia).
Constipation.
Headaches.
Preventing hair loss.
Darkening gray hair.

Applied to the Skin:

To prevent sunburn: PABA sunscreens come in concentrations of 1% to 15%.

PABA is SAFE for most people when applied directly to the skin. There have not been any reports of significant harm, although there have been reports that PABA increases the likelihood of sunburn in some people, even though it usually works as a sun block.

PABA is SAFE when taken by mouth appropriately and when applied to the eyes as a solution. PABA can cause skin irritation and might also stain clothing with a yellow color. Nausea, vomiting, upset stomach, diarrhea, and loss of appetite might sometimes occur.

PABA is POSSIBLY UNSAFE when taken by mouth in high doses. Taking more than 12 grams per day can cause serious side effects such as liver, kidney, and blood problems.

Children: When applied directly to the skin, PABA is SAFE for children. PABA is SAFE for children to take by mouth appropriately. Dose is important, as serious side effects can occur. PABA is POSSIBLY UNSAFE when taken by mouth in high doses. Some children who took doses of PABA greater than 220 mg/kg/day died.

Pregnancy and breast-feeding: PABA is SAFE when applied to the skin during pregnancy or breast-feeding. However, there is not enough reliable information about the safety of taking PABA by mouth if you are pregnant or breast-feeding. Stay on the safe side and avoid use.

Bleeding disorders: Using PABA intravenously (by IV) might increase the risk of bleeding in people with bleeding disorders.

Kidney disease: PABA might build up in the kidneys making kidney disease worse. Do not use it if you have kidney problems.

Surgery: Using PABA intravenously (by IV) might increase the risk of bleeding during surgery. Stop taking PABA 2 weeks before surgery.