Should men take testosterone when their testosterone level is low?
The answer is yes, if the man involved has a medical condition that deprives him from making testosterone. The answer is less clear when the man is otherwise normal, but his testosterone levels have dropped due to normal aging. When men with low testosterone levels take testosterone, they feel better and have a sense of greater energy, better mood, better sexual function, increased muscle mass and decreased body fat.
What male wouldn’t want those benefits? The drawbacks to taking testosterone are the concerns for increased heart disease and increased prostate cancer due to taking testosterone. There is a parallel here to women taking estrogen when estrogen levels drop. Taking estrogen is associated with increased risk of stroke, blood clots and cancer.
The risk of developing prostate cancer when taking testosterone seems to be low. This is important because lowering testosterone levels is a strategy in treating prostate cancer so it would stand to reason that raising testosterone levels would lead to prostate cancer. However, there is no evidence of this from clinical research. Perhaps this indicates a difference between testosterone made by a man’s body and testosterone taken from an external source. The former spurs prostate cancer but the latter does not.
So that leaves the concern for the possibility increased heart disease from testosterone therapy. This was the subject of a review by Jemma Hudson and others published in June in The Lancet, Healthy Longevity. The authors combined information from 35 clinical studies and had access to data of individual participants in 17 of those studies. This meant they had access to relevant information regarding testosterone treatment and its side effects or bad effects in 3431 men. Usually in medical studies, the greater the number of participants, the better the advice resulting from the research.
The men provided information over a range of time from 12 weeks to 3 years and the average was 9.5 months. Hudson and colleagues found there was no difference with respect to onset of heart disease or death due to heart disease when comparing the group of men who were taking testosterone as compared to the group of men who were not. They also noted that there was no difference between groups with respect to incidence of prostate cancer or blood clots.
So, it would be fair to say that men taking testosterone during a time frame that extends up to 3 years do not have to be concerned about new prostate cancer or new heart disease caused by testosterone. This helps some men who need short to intermediate term replacement of testosterone, but the big outstanding question remains, is it safe for men to take testosterone for decades since testosterone levels in men start to drop in their 30s. That question is not ignored and is the subject of an ongoing study that started in 2018 and will wrap up later this year and involves 5246 men. This will provide information over a 5 year follow up period as to whether there is increased heart disease in men taking testosterone over 5 years. If the answer to that question is no, then expect the prescription of testosterone for age related low testosterone to become more frequent.