December 1, 2015






Carcinogenesis, Mutagenesis, Impairment of Fertility

Long term studies with thymosin alpha 1 have not been done to determine carcinogenicity. Mutagenicity studies with thymosin alpha 1 showed no adverse findings.

Pregnancy Category C

Teratology studies in mice and rabbits have shown no difference in fetal abnormalities in control animals and animals given thymosin alpha 1. It is not known whether ZADAXIN (thymalfasin) can cause fetal harm when administered to a pregnant woman or affect reproduction capacity. ZADAXIN (thymalfasin) should be given to a pregnant woman only if the benefits clearly outweigh the risks

Nursing Mothers

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when ZADAXIN (thymalfasin) is administered to a nursing woman.

Pediatric Use

Safety and effectiveness have not been established in patients below the age of 18 years.

This monograph has been modified to include the generic and brand name in many instances.

Last reviewed on RxList: 3/3/2009


Report Problems to the Food and Drug Administration


You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Women's Health

Find out what women really need.