Active Ingredient

Cyproheptadine

Cyproheptadine is an antihistamine used to relieve allergy symptoms. It is also sometimes used to stimulate appetite in certain conditions.

This medication can help manage symptoms such as sneezing, itching, watery eyes, and runny nose.

Written By Douglas C. Goldberg, MD

Reviewed By Philip Schein, MD

Last Updated 28 Nov 2025

Available Cyproheptadine Brands

Periactin

Strengths 4mg

Cyproheptadine Uses

Cyproheptadine is commonly used for the following conditions:

Allergic reactions such as hay fever and urticaria.
Appetite stimulation in underweight individuals.
Prevention of migraine headaches.
Management of cold-related symptoms.

How Cyproheptadine Works

Cyproheptadine works by blocking the action of histamine, a substance in the body that causes allergic symptoms.

It also has antiserotonergic effects, which can help in preventing migraines and stimulating appetite.

By blocking these substances, it reduces symptoms like itching and swelling.

Common side effects of Cyproheptadine

Not everyone experiences side effects, and many are mild and temporary. Common side effects include:

Drowsiness
Dizziness
Dry mouth
Nausea
Increased appetite
Weight gain
Constipation

If you experience serious or persistent side effects, contact your doctor.

Frequently Asked Questions

How quickly does Cyproheptadine work?

Cyproheptadine may start to relieve symptoms within a few hours. However, the full effect can vary depending on the individual and the condition being treated.

Can Cyproheptadine be used long-term?

The duration of use should be determined by a healthcare professional based on your specific condition and response to treatment.

Is Cyproheptadine safe for everyone?

Cyproheptadine may not be suitable for individuals with certain medical conditions. It’s important to discuss your health history with a doctor before starting this medication.

Can I take Cyproheptadine with other medications?

Cyproheptadine can interact with other medications, so it’s crucial to inform your healthcare provider about all the drugs you are currently taking.

Does Cyproheptadine cause weight gain?

Increased appetite and weight gain are possible side effects. If you are concerned about weight changes, consult your doctor for advice.