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Pharmacy and Medications




Hi pharmacist,

I wonder why Cyproheptadine is used for anorexia because when I check the information from many reliable source, this medicine is almost the same like Benadryl, antihistamine for the treatment of allergy and anaphylaxis, hay fever, and something like this.

Can you explain to me why this medicine is also indicated as appetite stimulant and for how long can I take this medicine if I don`t have a good appetite?


You are correct. Cyproheptadine is an Antihistamine approved by the FDA for the treatment of seasonal allergies. However, Cyproheptadine is also used outside the FDA approval for migraines, schizophrenia, as an antidote for certain antidepressants overdose, and as an appetite stimulant.


In addition to its Antihistamine activity, Cyproheptadine is unique because it also inhibits the release of Serotonin. Serotonin is thought to play a role in suppressing appetite when it is available in high amounts in certain part of the brain called the ‘Hypothalamus’. Therefore, when Cyproheptadine is used, it decreases the amount of serotonin in the brain which may stimulate the appetite in an individual, leading to weight gain. This occurs in about 1-10% of the population. The usual dose of Cyproheptadine for appetite stimulation is 2 milligrams 4 times daily. However, there is no specific time limit to how long Cyproheptadine is used, because the increase in appetite occurs as long as the medication is in your body. Once you stop taking the medication, then most likely the medication will stop working as well.


In addition, Cyproheptadine may be associated with side effects such as drowsiness and dizziness which may impair your daily activity. Overall, the medication is safe to use, but it is always recommended to get your primary physician's opinion regarding the medications you are taking. 


Thank you for your question.


Submitted by Husam Sweidan, PharmD Candidate

The Ohio State University College of Pharmacy

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Response by:

Carmen M Hadley, RPh, CSPI
Former Clinical Instructor
College of Pharmacy
The Ohio State University