The randomised, placebo-controlled trial investigated the effect of supplementation with achiote plant extract (GG) or a placebo (PLA) in a group of 66 males and females for eight weeks, with dose escalation from 150 mg to 300 mg in the treatment group.
“GG supplementation may be beneficial for testosterone enhancement in male populations subject to low testosterone (i.e., aging males and those with late-onset hypogonadism),” the authors from the Applied Science and Performance Institute in Tampa, FL concluded.
The research, published in the journal Nutraceuticals, was funded by U.S. ingredient manufacturer American River Nutrition, which supplied the GG-Gold used in the study.
GG as testosterone booster
Annatto, a pigment extract from the tropical South American plant Bixa orellana (achiote), contains geranylgeraniol (GG), a key component with various health benefits. GG is primarily obtained in humans through endogenous synthesis via the mevalonate pathway, a metabolic pathway which plays a key role in multiple cellular processes by synthesising sterol isoprenoids.
GG supplementation has been previously linked to anti-inflammatory effects, is an essential building block for vitamin K2 and CoQ10 and has recently shown potential benefits for glucose regulation, bone health and the gut microbiome. Recent research has also endeavoured to explain the relationship between GG and steroid hormones.
The link between GG and testosterone is still being explored, but research indicates that GG can stimulate testosterone production in Leydig cells, which play a crucial role in regulating testosterone production and are essential for male reproductive system development. Insufficient testosterone levels can lead to infertility and sexual dysfunction, causing late-onset hypogonadism (LOH) in men common in older populations.
While testosterone replacement therapy is a common treatment, the long-term health effects of testosterone administration can be controversial, and therefore the authors suggest that GG could present a natural alternative.
Study details
The participants (aged 30-49 years) consumed either soft-gel capsules of GG (trans-Geranylgeraniol GG-Gold) or a visually identical placebo for eight weeks. For the first four weeks, participants in the active group consumed one soft-gel capsule in the morning and one at night, with the morning capsule mimicking the placebo and the evening capsule containing 150 mg of GG from 210 mg trans-Geranylgeraniol GG-Gold. During the last four weeks of the study period, participants in the active group were given morning capsules that also contained 150 mg of GG.
“The rationale for the study dosing of 150 mg and 300 mg was to assess a dose-response that was based on approximate human equivalent doses from animal studies,” the authors explained.
At the beginning and end of the eight weeks, the study analyzed changes in complete blood count and comprehensive metabolic panels for the study group as a whole (males and females) but evaluated changes in sex hormone panels for males and females independently.
The authors noted that while the purpose of the study was to determine the safety of GG and its impact on hormone levels in males and females, initial results showed that there were no significant changes in complete blood count, comprehensive metabolic panel, progesterone, estradiol, sex–hormone binding globulin or dihydrotestosterone.
However, as testosterone treatment is most commonly targeted for men in the lower range of the reference values for testosterone or men who are hypogonadal, the authors conducted an exploratory analysis to explore whether testosterone levels in participants had any impact on the efficacy of GG treatment.
This analysis in males below the 3rd quartile of total testosterone levels (<700 ng/dL) found a significant increase from baseline to week eight in total-, free- and bioavailable testosterone (+7.5%, +15.0%, and +14.8%, respectively).
The researchers added that outcomes of the study, conducted in healthy adult males and females, may not be applicable to wider clinical populations but that future research is warranted.
“We would hypothesise that specific populations, which tend to display hypogonadism (aging males) may exhibit more sensitive or robust responses to GG supplementation," they wrote. “The potential of GG as a testosterone enhancer in males with low testosterone, such as the aging male population and those with LOH, is a worthy research question to address in future studies.”
Source: Nutraceuticals
doi: doi.org/10.3390/nutraceuticals3040043
“The Effects of Geranylgeraniol on Blood Safety and Sex Hormone Profiles in Healthy Adults: A Dose-Escalation, Randomized, Placebo-Controlled Trial”
Authors: Raad Gheith et al.