Danazol increases telomeres, but we can’t recommend it.

Telomeres on Steroids

By Hector Valenzuela Ph.D.

Remarkably at every time point measured, the telomere length was elongated..

Hector Valenzuela Ph.D. 
RevGenetics CSO

Many years ago when I was writing my doctoral dissertation I tested different steroids ability to stimulate telomerase activity in human cells.

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At the time, our lab was very busy with different aspects of telomerase and telomeres and the results we were obtaining were very promising. These were also the last of my experiments before graduating from UCLA and at that time in all honestly, I was primarily interested in graduating.

Fortunately other labs were also testing steroids effect on telomeres/telomerase on human and rodent cells and many labs have since published interesting observations and made many discoveries on the relationship between hormones and telomere and telomerase biology. There are many practical applications that can be tested in this biology arena.

This month a group of researchers published an interesting angle, testing the effects of steroids on humans that have telomere shortening related disease in the hopes of amending their telomere shortening (New England Journal of Medicine, May 19, 2016, page 1922). The investigators used danazol (an hormone that increases the testosterone levels among its mechanism of action) on a group of 27 adults.

Before discussing the results I would like to point out the following. Normal cells of the blood (which were used as a point of reference) shorten their telomere at a rate of 60 base pairs per year. A person suffering from a telomere shortening related disease according to the authors shortens at a rate of 120 base pairs per year. So any telomere measurement that had a shorter level of telomere shortening was determined to be the end point.

The volunteer’s were given 800 mg of danazol and their telomere lengths were measured at 6, 12 and 24 month periods. Remarkably at every time point measured, the telomere length was elongated (in 11 of 12 patients). So much so, that the experiment was ended early and even though 27 patients were to be analyzed only 12 were needed.

In addition to the increased telomere length, the investigators also tested hematologic responses (which tested if the cells in the blood were produced at an adequate level) and the results indicated an improvement in cell production.

Although the results are remarkable, danazol has been shown to have side effects and is rarely taken for more than 6 months. But the proof of principle on what androgen steroids can achieve was clearly demonstrated. This study also supports the notion that other telomerase activators, such as TA-65, also merit further study given that they do not have the same side effects as danazol and may be a better alternative.

Why we don't recommend Danazol:

By Anthony Loera

​First the following is simply my opinion, and is not medical advice of any kind. Please review the following information, which I found online, with you doctor if you have questions. RevGenetics does not provide medical advice. I am only providing the following for informational purposes only. (Besides, I was curious myself).

​If you have read this far, then you know how important telomerase activation and/or telomeres are in relation to longevity and have probably already read Hector Valenzuela's summary of Elizabeth Blackburn's review on Human Telomeres: (Link to summary).

​From my perspective, and after a chat with Hector Valenzuela, I began to look at what a normal person would consider... mainly price and safety.

Price of Danazol, yes it is expensive:

From a Price perspective 800 mg of Danazol daily is expensive. Danazol is made with up to 200 mg a capsule. If I personally wanted to duplicate the study, I would be taking 4 capsules a day. A 90 capsule bottle with 200 mg capsules, runs about $236 a bottle. 4 bottles that would last me 90 days, would run me $944, I find that a bit high because of what we know about TA-65.

​I remind you that 1 bottle of TA-65 with 90 capsules, that lasts you for 90 days, has been shown to lengthen telomeres in humans and runs $600... and we have sold it ourselves for as low as $450 with free shipping recently because we price match other companies on the internet. Of course we also sell 30 capsule bottles for as low as $100 as well (Link to TA-65).

​In essence, if you are looking for a human study verified telomerase activation, we still suggest TA-65 90 capsules bottles... specially when the pricing fluctuates.

Safety of Danazol, yes it is a medication with contraindications and warnings:

From a safety perspective, TA-65 doesn't have the side effects and issues that I personally see Danazol can have. Here I provide a link on WebMD with the issues of Danazol: (Link to issues with Danazol). As a layman, I am forced to consider the safety of a medication along with the price.

​Bearing both in mind, I would not personally take Danazol as a telomerase activator, simply because of price but mostly because safety concerns at this time.

​Anthony Loera


About the author


    Anthony Loera is the President and Founder of RevGenetics. His posts provide information on Telomerase Activators, TA-65, Resveratrol and C60 Olive Oil.

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