In a recent study, a specialized extract of fenugreek (Trigonella foenum-graecum) as Testofen® (from Gencor Pacific)  increased testosterone levels, improved sexual function and reduced symptoms of andropause, a condition in men marked by falling levels of certain androgen hormones, namely testosterone.  Results of the double-blind, randomized, placebo-controlled trial appeared online ahead of print in The Aging Male journal.

Due to its reported effects on androgens, male hormones, Testofen is a popular dietary supplement for both sports nutrition (increase muscle mass) and sexual health. While this study did not focus on the muscle mass angle, it did focus partly on increased testosterone and could be of interest to sports nutrition users, especially men.

Acknowledging the causes of reduced testosterone in aging men (post-40 years of age) and both the clinical significance and the prevalence of such declines, researchers from Australia studied the effect of Testofen on 120 healthy men aged between 43 and 70 years of age. The men took either 600 mg/d of testofen or a placebo for 12 weeks. Each participant had a sex partner for the duration of the study, but there was a long list of exclusions related to health status and lifestyle actors. 

Researchers primarily looked at changes in the men’s Aging Male Symptom (AMS) questionnaire, which measures androgen deficiency symptoms. The questionnaire consisted of 17 questions in 3 sub-scales: psychological, somatic and sexual. The researchers used both these sub-scales and the total score to assess symptoms.

As secondary endpoints, the researchers looked at sexual function and serum androgen levels, specifically testosterone. They employed the Derogatis Interview for Sexual Functioning-Self Report (DISF-SR) questionnaire at baseline and completion (week 12) to assess sexual function. The test consisted of a set of 21 questions, with four sub-domains: sexual fantasy (SC), sexual arousal (SA), sexual behaviors (SB) and orgasm (O). They further drew blood from the subjects in the morning after an overnight fast at baseline, 6 weeks (mid-trial) and 12 weeks (completion). They analyzed the samples for serum total and calculated free testosterone, sex hormone binding globulin (SHBG), DHEA-S, androstenedione, oestradiol and prolactin.

At baseline and 12 weeks they also measured sleep quality, anthropometric  stats (weight, height, waist, hip, grip strength) and a host of health parameters including red and white blood cells, electrolyte and liver function and lipid profile.

Results showed no difference between active group (n=55) and placebo group (n-56) for age, anthropometric measures and lifestyle factors. Further, researchers found no correlation between age and total testosterone, but they did note a weak negative correlation between age and free testosterone. A negative correlation was also found between BMI and both total testosterone and free testosterone. They reported higher total testosterone level was associated with higher HDL cholesterol, but not with total or LDL cholesterol.

However, the results showed Testofen improved AMS score, compared to placebo. There was a significant difference across time and between groups for total AMS score and both somatic and sexual sub-scores. There was a significant difference across time, but not between groups, for psychology sub-score.

Results on hormones was mixed, as there was no difference between the groups for DHEA-S, androstenedione, oestradiol, SHBG or prolactin levels, but there was a small increase in testosterone and calculated free testosterone at week 12 in the Testofen group, compared to placebo.

The researchers said they still saw significant increases in both total and free testosterone in the Testofen group even after applying a Bonferroni adjustment—prior research on Testofen was criticized in a series of lawsuits for not using the Bonferroni correction method.

The researchers suggested possible mechanisms for the testosterone increases include stimulation of pulsatile GnRH/LH, increased testicular sensitivity to LH, and increased testosterone synthesis or reduced testosterone catabolism. The cautioned further study is needed to assess these possible mechanisms.

“These results provide a potential mechanism for the positive effects on somatic and sexual function observed in this study," the researchers wrote. “It is hypothesized that the reduction in severity of symptoms and increased somatic and sexual function was directly or indirectly related to the increased serum testosterone."

Testofen also improved sexual function, compared to placebo. There was a significant difference between the groups in total DISF-SR score and both the Sexual Arousal and Sexual Drive/Relationship sub-domains. There were no changes in the Sexual Cognition, Sexual Behavior or Orgasm sub-domains.

Testofen also appeared to improve frequency of erections. At the start of the study both groups reported an average of one erection per week, but after treatment (week 12) the Testofen group reported an increase to two to three erections per week, while the frequency remained unchanged in the placebo group. Likewise, both groups reported sexual activity of about one to two times per month, but only the Testofen group increased to once per week by the end of the study. The researchers noted these frequency trends were consistent with the AMS Sexual Function sub-domain scores.

The researchers noted the Testofen supplement was well-tolerated, except for reports of headache in less than 5 percent of subjects, which was also found in earlier research.

Based on these results, the researchers concluded,  “[Testofen] may become an alternative for symptomatic men where low or borderline testosterone is associated with obesity, chronic disease and mood disorder rather than organic hypothalamic–pituitary–testicular axis pathology. However, further studies are needed to establish its long-term safety and efficacy."