Cyproheptadine, the active principle of Apetamil belongs to a group of medications called antihistaminics. It acts blocking histamine H1 receptors while it relieves allergic reaction symptoms. Histamine is released when an allergen (such as pollen) enters the body and causes skin inflammation, itching and nasal congestion.
On the other hand, cyproheptadine is capable of blocking serotonin receptors at the brain level. Serotonin is a substance that plays an important role in appetite regulation. It is very likely that by altering serotonin activity in the appetite center in the hypothalamus, Cyproheptadine stimulates appetite, inducing an increase of food ingestion.