Neem leaf is used for leprosy, eye disorders, bloody nose, intestinal worms, stomach upset, loss of appetite, skin ulcers, cardiovascular disease, fever, diabetes, gingivitis, and liver problems. The leaf is also used for birth control and to cause abortions.
 
Cautions and Side Effects Of Neem:
 
Pregnancy and breast-feeding: Avoid use of Neem.
 
Children: Taking neem seeds or oil by mouth is LIKELY UNSAFE for children. Serious side effects in infants and small children can happen within hours after taking neem oil.
 
Diabetes: There is some evidence that neem can lower blood sugar levels and might cause blood sugar to go too low. If you have diabetes and use neem, monitor your blood sugar carefully. It might be necessary to change the dose of your diabetes medication.
Reduced ability to have children (infertility): There is some evidence that neem can harm sperm. It might also reduce fertility in other ways. If you are trying to have children, avoid using neem.

Organ transplant: There is a concern that neem might decrease the effectiveness of medications that are used to prevent organ rejection. Do not use neem if you have had an organ transplant.