Ketotifen Fumarate is an H1-antihistamine that is available in two versions oral and ophthalmic. In the ophthalmic (for use in the eye) form, it is used to treat conjunctivitis (pink eye), or the itchy red eyes caused by allergies. It is used orally as a medication to aid in the prevention of asthma attacks, and has also been used by many as a sleeping aid and appetite stimulant.


Ketotifen fumurate is sold under the brand name Zaditor. It is also available from many underground labs, typically for use with clenbuterol or sometimes mixed with it.


Ketotifen is an antihistimine that inhibits down regulation of beta receptors, which are often degraded by fat-burners such as Albuterol and Clenbuterol.

It can be used in combination with these other drugs in order to keep feeling their fat-burning effects for longer periods of time with out the need for periods of on and off cycling. Side effects can include drowsiness, irritability, nosebleeds and dry mouth. Ketoifen increases appetite; therefore another side effect is typically weight gain. Ketotifen also (potentially) improves insulin sensitivity within muscle tissue.

Technical Data

Because Ketotifen has the ability to stimulate the appetite, it has been studied for use with wasting conditions. In the most commonly referenced study examining this property, 22 AIDS patients who were administered Ketotifen and Oxymetholone, 18 gained an average of 11.4 pounds after just under 4 weeks (1). Further research proved Ketotifen to be a TNF-alpha blocker. TNF-alpha lowers testosterone and IGF-1 levels immensely (2,3) while strenuous exercise raises TNF-alpha levels (4). TNF-alpha has also been found to inhibit the muscle’s ability to uptake glucose, (which is known as insulin resistance). It has recently been discovered that hypogonadism and low testosterone are also associated with elevated TNF-alpha (5).

This would seem to indicate a potential use for Ketotifen in Post-Cycle Therapy.

User Notes

Ketotifen was first introduced to the bodybuilding world by Dan Duchaine, who proposed its use for upregulation of Beta – Receptors. Several years after his passing I figured out that Benadryl would work for the same purpose, and Ketotifen was largely abandoned for the more commonly available Benadryl.

It is, however, due to the late Karl Hoffman that we owe the use of Ketotifen for reducing TNF-a and for possible use in PCT. He pioneered this idea (though it didn’t really catch on, per se), and it would seem to be very beneficial as an anti-catabolic, though it’s cost would make it prohibitive for use in up-regulating Beta-Receptors.

Ketotifen - Zaditen
Ketotifen – Zaditen
Ketotifen - Zaditen
Ketotifen – Zaditen


  1. Smart T. GMHC Treat Issues. 1995 May;9(5):7-8, 12.
  2. Mauduit C, Endocrinology 1998 Jun;139(6):2863-8
  3. Lang CH Growth Horm IGF Res 2001 Aug;11(4):250-60
  4. Pedersen BK et. al. Exerc Immunol Rev 2001;7:18-31
  5. Malkin CJ J Clin Endocrinol Metab. 2004 Jul;89(7):3313-8.

(Assistance on this profile provided by Rosanne Clemente)