Male Sexual Health Supplements: A Doctor’s Guide
The sexual health industry is a rapidly growing market fueled mostly by straight-to-consumer advertising and promises of mind-blowing sex. The sexual health supplement world is a small microcosm of the larger dietary supplement industry, which has exploded in the last 30 years. Dietary supplement sales have increased dramatically in the last few decades from $9 billion in 1994 to more than $27 billion in 2016.
The massive growth in the supplement industry is due in part to the passage of the US Dietary Supplement Health and Education Act (DSHEA) in 1994, which permitted any substance to be promoted as a dietary supplement as long as no specific claims that the substance could treat, cure, mitigate, or diagnose any disease or condition were made on the label of its container. Supplements technically fall under the jurisdiction of the Food & Drug Administration, but those sold in the United States are not required to follow specific standards or to ensure quality control.
This has led to a kind of Wild West approach to the supplement market and concerns over not only efficacy but also safety. Recent independent analyses of several commercially available sex-enhancing supplements have found that one or more compounds advertised on the label could not be identified. Many sexual health supplements have also been found to have contaminants. Furthermore, there is very little clinical research is available on drug–supplement interactions (Moyad 2002).
I get asked all the time from patients about which supplements I recommend to enhance performance. Men and their partners are often interested in avoiding prescribed medications when they can in favor of more “natural” methods. If I were to attempt to cover every supplement out there that claims to improve male sexual health, we would be here all day. So what follows is a concise review of some of the more common male-enhancing supplements and a discussion of which of these supplements may actually work.
L-arginine is an amino acid that is used in the biosynthesis of proteins. It is also a precursor to nitric oxide (NO), which is crucial to allowing the blood vessels in your penis to dilate during sexual activity. Non-concentrated L-arginine exists in foods such as legumes, whole grains, and nuts, but it can also be taken as a concentrated supplement. Several randomized controlled trials have been conducted looking at the effects of L-arginine on erectile dysfunction (ED). These studies tend to have short treatment periods and have shown mixed results (Klotz 1999; Chen 1999; Rimando 2005). In men consuming 2800mg/day over a two-week period, improvements in penile blood flow as measured by ultrasound were noted. In another study, only 30% of men receiving L-arginine reported improvement in their erectile function. The potential positive effects of L-arginine seem to only be present when the supplement is ingested in large daily doses. Side effects such as abdominal pain, bloating, diarrhea, and low blood pressure may limit one’s ability to consume the necessary high doses to achieve the desired erection enhancement.
Korean Red Ginseng
Korean red ginseng is a plant native to Asia. As a supplement, it is generally consumed as a liquid, powder, or capsule but you can also buy dried red ginseng root to boil in water for tea. It has been linked to increased alertness and offers other possible benefits, including anti-platelet potential, preventing the common cold, and lessening the severity of heart disease and menopausal symptoms (Kim 2012; Kim 2013). A few small randomized-controlled trials have also suggested its potential benefit for erectile dysfunction, with up to 60% of men reporting improvement (Choi 2013; Hong 2002; Andrade 2003). Common adverse effects include headache, palpitations, dizziness, elevated blood pressure, and insomnia
DHEA is an endogenous steroid hormone precursor produced by the adrenal glands that get converted into testosterone and estrogen. Its secretion peaks at the age range of 25-35, gradually declining thereafter. By age 70, DHEA production is approx 10-20% of peak levels. DHEA can have both androgenic (testosterone) and estrogenic effects in the body depending on the specific tissues where it is acting.
DHEA supplements are typically derived from plants such as the wild yam. Commercially available DHEA supplements claim to enhance adrenal function, strengthen the immune system, help with anti-aging, improve energy, mood, and memory, and build bone and muscle strength. Studies demonstrating amelioration of ED with DHEA are mixed with some showing improved self-reported erection scores and others finding no difference from placebo (Reiter 1999; Reiter 2001; Morales 2009). DHEA is also used as a natural way to boost testosterone. This is based partially on its function as a prohormone to androstenedione and androstenediol, both precursors to testosterone. However, studies looking at the treatment of hypogonadism (low testosterone) with DHEA have shown increases in DHEA, androstenedione, estradiol, but not testosterone (Corona 2013).
The adverse effects of DHEA can occur from estrogen or testosterone-mediated changes. These include oily skin and acne, skin thickening, hair loss, high blood pressure, facial hair, fatigue, headache, insomnia, and unfavorable changes in cholesterol levels.
Tribulus is a flowering plant found in tropical and temperate climates with a wide range of reported positive effects as a diuretic, aphrodisiac, anti-diabetic, antioxidant, anti-inflammatory, analgesic, anti-cancer, and antibacterial substance (Chhatre 2014). The effects are possibly related to saponins and flavonoids in the compound, or mediated through increases seen in DHEA.
Improvements in sexual satisfaction, orgasm, and desire have been reported with the use of Tribulus (Kamenov 2017). And unlike many of the compounds we’ve discussed, no significant difference in adverse events have reported between Tribulus and placebo groups. When it comes to erections, the significance of reported improvement is controversial when compared to placebo (Kamenov 2017, Santos Jr. 2014, Adimoelja 2000, Sansalone 2014). With regard to boosting testosterone, again the results are mixed. Some small studies have demonstrated statistically significant increases in testosterone in men treated with Tribulus while others have shown no difference (Roaiah 2016, Kamenov 2017)
Gingko Biloba has been used to treat peripheral vascular disease for decades. It has also been promoted as a libido booster and a treatment for ED. Unfortunately, this is not supported by science. Two placebo-controlled trials looking at the potential benefits of Gingko Biloba demonstrated no improvement in ED (Kang 2002, Wheatley 2004). Significant toxicities including headaches, major bleeding, and seizures with a reported fatality, have also been reported.
Citrulline is a non-essential amino acid that is converted to L-arginine and nitric oxide in the kidney. It is thought to increase NO levels more efficiently than L-arginine, possibly because it bypasses liver and intestinal bacteria metabolism (Safavi-Hemami 2010). And more nitric oxide means more blood flow to your erection.
L-citrulline is abundantly contained in watermelon, pumpkin, garlic, and cucumber, so your mom may have been on to something when she harped on you to eat your fruits and vegetables.6 In animal models, L-citrulline has been shown to improve penile blood flow (Shiota 2013). In human studies, improvements in the erection hardness scale have been reported in men with mild-to-moderate ED who were treated with L-citrulline (Cormio 2011). Deficient levels of both L-citrulline and L-arginine may also increase the risk of arteriogenic erectile dysfunction (Barassi 2017). Like arginine, L-citrulline dosing may limit its potential benefits. It must be taken generally in large amounts daily, sometimes even multiple times per day to be effective. Some common side effects include upset stomach, heartburn, cough, changes in urination, swelling, and low blood pressure.
Horny Goat Weed
You may have seen horny goat weed (HGW) at your favorite liquor store or your neighborhood gas station. It is a popular male sexual health supplement that comes from the extract of the Epimedium plant, which is a flowering perennial found throughout Asia and parts of the Mediterranean. HGW contains low levels of icariin, a flavonol glycoside that has been shown to have similar effects to medications like Viagra (Cui 2015). Improvements in penile blood flow have been demonstrated in rats, but no clinical trial data in humans are available. Side effects associated with horny goat weed are rare, but heart arrhythmias and hypomania have been reported (Partin 2004).
Tongkat Ali is an herbal supplement that comes from the roots of the green shrub tree Eurycoma longifolia, which is native to Southeast Asia. It is thought to improve libido, erectile dysfunction, and testosterone but most of these presumed effects are based on in-vivo animal models (Ang 2001, 2002, 2004). The possible mechanism involved in improving male sexual performance is associated with increased conversion of pregnenolone to progesterone, cortisol, DHEA, and testosterone in corpus cavernosum (erectile) tissues (Ang 2003). Two randomized controlled trials reported an increased number of intercourse attempts and improved scores of penile erection hardness, and sexual well-being of subjects (Udani 2014; Tambi 2012). A few placebo-controlled trials have demonstrated increased serum testosterone levels as well as improvements in libido and overall sexual performance. Tongkat Ali is even thought to play a role in improving semen parameters (Thu 2017). There are little to no reported serious adverse effects associated with Tongkat Ali supplementation.
Zinc deficiency is associated with low T and supplementation in deficient individuals has been shown to reverse hypogonadal effects (Sandstead 1967; Prasad 1996). Thankfully, zinc is plentiful in modern Western diets and true deficiency is rare. Despite the benefit of zinc on hypogonadal men, there is no evidence that zinc supplementation in normal individuals increases serum testosterone and no clear evidence that repletion improves sexual performance or libido (Cui 2015). Side effects from zinc supplementation are typically mild.
Selenium is a powerful antioxidant that has been studied in prostate cancer prevention but has no clear benefit for its use in improving sexual health. Moreover, antioxidants, in general, show some promise in animal studies but there are no clinical data demonstrating improvements in ED with antioxidant supplementation.
Vitamins have been shown to help fight cancer, heart disease, and the ravages of aging, but their role in improving sexual health remains up in the air. One study reported better erectile function scores among diabetic patients when vitamin B6 was combined with a PDE5 inhibitor (PDE5i, think Viagra) than with PDE5i alone (Hamidi 2013). Vitamin E has also been used for decades in the treatment of Peyronie’s disease, a condition resulting from fibrous scar tissue that develops on the penis and causes erection deformity, despite no good evidence of improvement in penile curvature or plaque size (Hauck 2006).
The dietary supplement market is a multi-billion dollar industry that has grown dramatically in the last few decades. Supplements focused on sexual health are becoming increasingly popular with straight-to-consumer marketing and advertising, especially on social media platforms. As we have seen, most assertions regarding the efficacy of supplements in improving certain aspects of male sexual health are based on animal models or a small number of clinical trials. Widespread discrepancies have been reported with many products either containing contaminants or not containing substances listed on the nutritional label. It is important to also check with your healthcare provider to make sure the supplement you are considering does not interact with any other medications you may be taking. Before you add one of these “male-enhancers” to your cart, always remember to weigh the potential risks and benefits.
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