Nettle leaf extract is a popular ingredient in testosterone-boosting supplements. Many of these supplements claim that nettle leaf can help fix low testosterone issues in men. But does nettle leaf actually have the potential to improve testosterone levels?
The short answer: Nettle leaf seems to have some mild estrogen blocking effects, but it isn't going to substantially raise testosterone levels. It's a reasonable secondary ingredient in supplements designed to raise testosterone, but it's not likely to make a large difference by itself.
Before we dive into the details, let's clarify some important facts around the studied results that lead to claims around nettle leaf and testosterone:
Contrary to popular belief, there are no studies that directly link nettle leaf to the production of testosterone in the body. While nettle has been added to various testosterone boosters, its effects on testosterone are more indirect. However, nettle has been found to be extremely beneficial for prostate health. A study conducted on 558 test subjects found that nettle extract is useful in treating benign prostatic hyperplasia (prostate enlargement) and associated urinary complications, which in turn coulf have a positive impact on testosterone levels, but this is tangential at best.
What it does effect is free testosterone levels. Free testosterone refers to the amount of testosterone in the bloodstream that is not bound to proteins, such as sex hormone-binding globulin (SHBG) or albumin. It is the biologically active form of testosterone and is available for use by the body's tissues. Free testosterone levels are important in determining an individual's hormonal balance and can have an impact on various aspects of health, including sexual function, muscle mass, bone density, mood, and energy levels.
To understand how nettle leaf affects testosterone levels, we need to explore two crucial mechanisms in the body: aromatase and Sex Hormone Binding Globulin (SHBG).
Aromatase is an enzyme that converts androgens (such as testosterone) to estrogens, leading to a decrease in testosterone levels. Several research studies have found that nettle roots have aromatase-inhibiting properties, which means that nettle supplementation can reduce the conversion of testosterone to estrogen. In fact, the European Medicines Agency included an extensive study on the aromatase inhibition ability of nettle extract in their assessment report.
Additionally, nettle extracts have been found to inhibit the binding activity of SHBG, a protein that attaches to free testosterone, rendering it inactive. By preventing SHBG from binding to testosterone, nettle increases the bioavailability of testosterone in the body.
One proposed mechanism is the inhibition of the 5α-reductase enzyme, which converts testosterone into dihydrotestosterone (DHT) (Chrubasik et al., 2011). DHT is a potent form of testosterone that plays a role in the development of the prostate gland and the progression of conditions like BPH. By inhibiting this enzyme, nettle leaf may help maintain a more balanced ratio of testosterone to DHT.
It's worth noting that there are also several studies that suggest Nettles do not raise testosterone levels. For example another study aimed to investigate the effects of nettle root extract on lower urinary tract symptoms and testosterone levels in men. The results showed that nettle root extract significantly improved lower urinary tract symptoms. However, the study did not find a significant change in total testosterone levels or free testosterone levels after the intervention although it did record them. These findings suggest that while nettle root extract may be beneficial for managing urinary issues caused by prostate conditions, but nettle leaf's impact on testosterone levels requires further investigation.
While nettle extracts do not directly increase testosterone production, there is some evidence to suggest they have a positive impact on testosterone health. Some early research suggests that nettle extracts could inhibit aromatase and prevents the binding of SHBG to testosterone, thereby maintaining and protecting testosterone levels. However, it's important to note that further research is needed to fully understand the mechanisms and potential benefits of nettle supplementation on testosterone levels.