Non-stop long-term steroids use reduces life span, says animal study

Athletes who are continuously using anabolic steroids are probably reducing their life expectancy. Biologists at the University of Texas draw this conclusion in an animal study published last century in Medicine and Science in Sports and Exercise.

Anabolic steroids
Before Franklin Bronson and Curt Matherne published their study in 1997, researchers had only studied the health effects of anabolic steroids in animal studies that lasted a few weeks. There had been no studies on the effects of extended use.

Because the researchers realised that considerable numbers of athletes were continuously juicing for years on end, they decided to study the effect of steroids use over long periods in mice.


The researchers gave male mice implants that continuously released testosterone, methyl testosterone, norethandrolone [structural formula shown on the right] and testosterone cypionate (all anabolic steroids) into the blood. The mice were about two months old when they were fitted with the implants. In human terms they were young adults. They’d just got their driving licence.

The researchers kept the implants in the mice for 6 months, after which they removed them and then watched what happened to the mice in the following year. The experiment lasted a total of 20 months. Lab mice can reach an age of about 26 months. So the experiment stopped when the mice, in human terms, were in their sixties.

The researchers had divided the mice into three groups. One group was given implants that released no hormones [Control].

Testosterone Cypionate
Another group was given implants that released doses of anabolic steroids that are considered ‘mild’ in steroids users’ circles. If we’re talking about testosterone cypionate [structural formula shown above], then the human equivalent of the dose the mice were given would be about a couple of hundred milligrams a week. [Low dose]

The third group of mice were given their steroids cocktail in a dose that was about four times that given to the Low Dose group. [High Dose].

At the end of the experiment, 12 percent of the mice in the control group had died. Of the mice that had been given a low dose of steroids, 33 percent had died. Of the mice that had been given a high dose of steroids, 52 percent had died.


The researchers tried to establish the cause of death of all mice that had not made it to the equivalent of human retirement age. The picture that emerged, which is shown below, is pretty diverse. There was not one specific cause of death that stood out.


The fatal liver tumours and cases of peliosis hepatitis were probably a consequence of the norethandrolone and methyl testosterone, the researchers wrote. It is well known that 17-alpha-alkyl steroids can cause liver damage, and most steroids users take this into account when designing their cycles. But even if you disregard these effects, the causes of death remain diverse.

“Perhaps the most important result of the present study is the demonstration that exposure to steroids produces a broad array of pathological effects that do not appear until long after exposure to steroids ceases”, the biologists wrote in the last paragraph of their publication.

“There is little comparable data for humans. Widespread use of steroids did not occur until the 1970s and, probably more germane, the practice of ‘stacking’ or combining several analogues of testosterone at suprapharmacological levels did not become common until the 1980s”.

“Thus, the delayed effects of steroid abuse seen here in mice and the consequent dramatic effect on life span may ultimately prove to be a concern for athletes and body builders abusing steroids regardless of specific pathological condition.”

Exposure to anabolic-androgenic steroids shortens life span of male mice.


Adult male laboratory mice were exposed for 6 months to a combination of four anabolic-androgenic steroids of the kinds and at the relative levels to which human athletes and body builders expose themselves. The four steroids included testosterone, two 17-alkylated steroids, and an ester, and they were given at doses that totaled either 5 or 20 times normal androgenic maintenance levels for mice. By the time the survivors were 20 months old (1 yr after the termination of steroid exposure), 52% of the mice given the high dose of steroids had died compared with 35% of the mice given the low dose and only 12% of the control mice given no exogenous hormones (P < 0.001). Autopsy of the steroid-treated mice typically revealed tumors in the liver or kidney, other kinds of damage to these two organs, broadly invase lymphosarcomas, or heart damage, and usually more than one of these conditions. It can be concluded that the life span of male mice is decreased dramatically by exposing them for 6 months to the kinds and relative levels of anabolic steroids used by many athletes and body builders. PMID: 9140897 [PubMed - indexed for MEDLINE] Source: