What to do against low testosterone – Replacement, SERMs, SARMs or something else?

There’s a new review paper on an interesting topic, titled “Novel Therapy for Male Hypogonadism” from Miami University. We are let known that the last author of the paper [1] was the lead investigator of a drug trial in the past (Natesto, a formulation of testosterone for hypogonadism). The researchers are from Miami. Whether its tropical climate and beautiful beaches play a role on choice of the topic, remains unknown.

Low testosterone

Word ‘hypogonadism’ comes from Ancient Greek – hypo meaning sub-; gonad meaning seed). Hypogonadism is a clinical entity diagnosed with repeated measurement of low testosterone. Clinically, age-related hypogonadism is a type of sexual development delay in boys. Late-onset of hypogonadism can resemble some aspects of old age that are not liked very much by older men.

The paper discusses the recent papers on the clinical meaning of hypogonadism. One of the key issues is that older men with the hypogonadism complaints do not have low testosterone and vice versa.

Several treatment options are available. In addition to physical activity and lifestyle modification that is very important for late-onset hypogonadism. Testosterone replacement treatment is the approved treatment while several experimental treatment options have been used as off-label treatments or in scientific studies.

Testosterone replacement is effective against hypogonadism symptoms. But is likely to adversely affect endogenous testosterone production and fertility parameters.

Selective estrogen receptor modulators (SERMs)

Selective estrogen receptor modulators (SERMs) have different estrogenic and antiestrogenic activity. SERMs such as tamoxifen and clomiphene improve serum lipids and bone density but tend to increase the incidence of venous thrombembolia. A SERM, Clomiphene citrate works by reducing negative feedback from estradiol to hypothalamus. That is at the top of cascade leading to testosterone production. Clomiphene is quite widely used by doctors despite indication being off-label. Clomiphene raises rather than suppresses endogenous testosterone, and spares fertility, and the cost to the patient is lower.

Aromatase inhibitors such as anastrozole and exemestane work by reducing conversion of testosterone to estradiol. Estradiol in low doses has beneficial effects but increased levels of estradiol cause undesirable effects other than negative feedback to hypothalamus as well. That can be summarized as feminization. While clomiphene is better at increasing testosterone concentration, aromatase inhibitor anastrozole was better at increasing testosterone : estradiol ratio.

Human chorionic gonadotropin (HCG) can raise endogenous testosterone production but also FSH is necessary for preservation of fertility. HCG has been used to treat azoospermia caused by steroid abuse. It may be combined with testosterone replacement to preserve the intratesticular levels of endogenous testosterone and and normal semen parameters.

Anabolic steroids such as nandrolone have also been revisited, lately, and considered as possibilities alternative to testosterone replacement because anabolic steroids have desirable effect of muscle selectivity


Finally, SARMs are considered as a novel option for testosterone replacement treatment. The selectivity of SARMs is more desirable than that of anabolic steroids, largely lacking androgenic activity in prostate or sebaceous glands, therefore making these compounds interesting for future pharmacy. However, as is often the case with novel substances – more research is needed before more widespread application may take place.


One may only wonder, which of the above would be the first to be considered as an alternative to testosterone replacement treatment first.