Horny Goat Weed vs. Viagra: Which Is Better for ED?

Horny goat weed versus Viagra^®: Is the former as effective as the latter for treating erectile dysfunction (ED)?

With a name like horny goat weed, this natural supplement sure sounds like it’ll help you perform in the bedroom. But a little digging makes one thing clear: Between these supplements and legitimate medications approved by the FDA (U.S. Food and Drug Administration) to treat erectile dysfunction, there’s really no comparison in safety and efficacy.

Over-the-counter supplements and other products touted as ”natural Viagra” make big claims, but few are supported by clinical trials. Generally, dietary supplements are held to different (lower) standards across the board compared to FDA-approved medications.

Unlike pharmaceuticals, which require FDA approval to ensure their safety and effectiveness before being sold, dietary supplements don’t undergo the same pre-market evaluation for safety by the FDA.

But that’s just scratching the surface.

Below, we’ll cover why some people use horny goat weed for ED, how well it works, and how the wellness supplement compares to ED medications like Viagra.

Curious how horny goat weed measures up to tried-and-true ED medications? Here’s a quick rundown of horny goat weed versus Viagra:

• Horny goat weed is an informal name that refers to various herb species of the Epimedium genus. These plants have been used in traditional Chinese medicine for centuries and are sometimes called ”yin yang huo.”

• Like many other herbal supplements, there’s limited evidence that horny goat weed offers any health benefits.

• Some research on animals suggests that icariin, a compound in horny goat weed, might support blood flow to the penis by inhibiting the effects of phosphodiesterase-5 (PDE5) — the same enzyme medications like Viagra block (more on that below). However, only a small amount of research compares horny goat weed to FDA-approved PDE5 inhibitors such as sildenafil.

• For now, Viagra (sildenafil) remains a safe and more effective treatment for ED because it works quickly (in as little as 30 minutes) and has been studied extensively compared to horny goat weed.

In short, much more research on horny goat weed is needed before we can confidently say whether it’s a worthwhile treatment for erectile dysfunction.

Erections depend on a combination of proper nerve function and healthy blood flow. When you feel sexually aroused, your brain sends signals through your nervous system to relax the smooth muscles in the arteries supplying blood to your penis.

As blood flows into the erectile tissues of your penis (called the corpora cavernosa), a fibrous sheath called the tunica albuginea helps trap this blood. This allows you to sustain an erection during sexual activity.

The enzyme involved in this process is called phosphodiesterase type 5, or PDE5.

PDE5 is found inside the smooth muscle cells of blood vessels, playing a key role in controlling blood flow. When the enzyme’s effects are slowed down or stopped, blood vessels can relax, and blood can more easily flow to certain parts of the body, including the penis.

Oral medications for erectile dysfunction — such as sildenafil (the active ingredient in Viagra), tadalafil (Cialis^®), vardenafil (Levitra^®), and avanafil (Stendra^®) — belong to a class of drugs known as PDE5 inhibitors.

These medications work by reducing the effects of PDE5 and making it easier for blood to flow into your penis when you’re sexually aroused. Some believe horny goat weed works similarly to inhibit the PDE5 enzyme, but the research is scant. More on this ahead.

Explore some of the most common ED treatments here.

The horny goat weed plant (Epimedium grandiflorum) is native to China and Korea. Its unique nickname can — supposedly — be traced back to a Chinese goat herder, who reportedly noticed increased sexual activity in his herd after the goats ate its leaves.

Horny goat weed has been used as an ingredient in traditional Chinese medicine for centuries.

It’s generally considered an aphrodisiac and yang tonic (as in yin-yang — a remedy that re-balances the body when energy is low). Some believe horny goat weed enhances the ”energetic organ” (kidney) while promoting fertility and sexual function. And some research suggests horny goat weed works like sildenafil. 

Theoretically, the leafy plant may inhibit the effects of PDE5 and improve blood flow to certain parts of the body — including the penis. But unlike sildenafil, its risks aren’t as well understood, and it’s not clear if it even works in the first place.

In traditional Chinese medicine, epimedium has historically been used to treat cardiovascular health issues, including those affecting the circulatory system. It’s also purported to offer other benefits, like improving symptoms of osteoporosis.

Proponents of horny goat weed typically point to a compound in it called icariin as a source of its potential benefits.

It’s important to point out that most of the existing scientific research on horny goat weed has been carried out in a lab setting. A few studies have examined its effects on animals, but human research is limited.

Horny Goat Weed Effects in Humans

When it comes to research involving humans, there isn’t very much to support horny goat weed as a treatment for any real diseases or health conditions.

However, a few studies have produced interesting findings.

One double-blind, placebo-controlled study published in the Journal of Bone and Mineral Research in 2007 involved 100 postmenopausal women. It found that compounds derived from epimedium (called “epimedium-derived phytoestrogen flavonoids”) may help prevent bone loss.

To fully understand the extent of horny goat weed’s benefits for human health, more research is needed.

Even though horny goat weed is among the most popular ingredients in sexual health and erectile enhancement supplements, there’s very little high-quality research showing that it actually treats ED.

A few animal studies have supported the theory that horny goat weed helps improve erectile function by inhibiting PDE5, but more research is needed to confirm this hypothesis.

Research on Horny Goat Weed for Erectile Dysfunction

In 2013, a double-blind, placebo-controlled study published in the African Journal of Traditional, Complementary and Alternative Medicines found that a supplement containing epimedium improved erections in men with mild to moderate erectile dysfunction.

But the supplement used in this study also contained several other ingredients. So it’s impossible to know whether the benefits were caused by horny goat weed, another ingredient, or a combination of active ingredients.

Other research has suggested that icariin may improve erectile function based on findings seen in castrated rats.

More animal research has shown icariin may improve atherosclerosis (a buildup of plaque in blood vessels). Atherosclerosis is a common risk factor for ED, and icariin might help due to its antioxidant, anti-inflammatory, and lipid-modulatory effects.

Still, remember that substances that work for treating ED or other medical conditions in animals might not always have the same benefits in humans. The only definitive way to determine this is through rigorous clinical trials that compare the ingredient to a placebo.

Also, keep in mind that the anecdotal reports you often find in blog posts and online reviews of horny goat weed don’t necessarily mean it’s a practical option for treating ED or improving blood flow.

Again, we need more studies before we can confidently say whether horny goat weed offers any serious benefits for sexual dysfunction or other male sexual performance issues.

Like other supplements, horny goat weed may cause potential side effects. Reported adverse effects of horny goat weed extract and its active ingredients (icariin and epimedin) include:

• Nausea

• Abdominal discomfort

• Skin rash or allergic dermatitis

• Irregular heartbeat

Currently, there are no long-term toxicity studies looking at the safety of horny goat weed or icariin. But the current research suggests that some horny goat weed extracts can be safely used for several months at a time without significant issues.

There have been reports of cardiovascular issues, including arrhythmias (irregular heart rate), in people using horny goat weed supplements around the time of surgery.

Because of this, doctors may recommend stopping the use of these and other supplements up to two weeks before a procedure. Your best bet is to talk to your healthcare provider before using horny goat weed or any other sexual health supplements.

This conversation is particularly crucial if you already use prescription medication or if you’ve been diagnosed with a health condition like cardiovascular disease.

Horny Goat Weed Drug Interactions

Research suggests that horny goat weed may interact with certain medications and supplements, including those broken down by the liver.

In rat studies, horny goat weed has been shown to affect how quickly the liver can metabolize some medications, such as those targeted by enzymes CYP1A2, CYP3A4, and CYP2E1, like sildenafil and other ED medications. This could cause these drugs to produce different effects or side effects.

Beyond that, horny goat weed may interact with anticoagulants and antiplatelet medications due to its antiplatelet and antithrombotic effects. This could result in an elevated risk of bleeding or bruising.

Finally, horny goat weed might interact with medications and supplements that reduce blood pressure, causing a potentially dangerous reduction in blood pressure.

To avoid drug interactions, inform your healthcare provider about any supplements and medications you currently use or have recently used before taking horny goat weed.

It’s unclear how fast horny goat weed works or how long it stays in your system because there’s not enough research on humans.

In contrast, extensive clinical trials have provided clear data on how quickly Viagra and its active ingredient, sildenafil, take effect.

Viagra typically starts working within 30 to 60 minutes after taking a standard dose (usually 50 milligrams for most men) and helps treat erectile dysfunction. It can be taken anywhere from 30 minutes to four hours before sexual activity but shouldn’t be used more than once a day.

Though research is limited on the effects of horny goat weed, a few existing treatments for erectile dysfunction are backed up by real evidence and science.

Of these, the most popular are oral PDE5 inhibitors, which work by increasing blood flow to the penis. These come in tablet form and are designed for use around one hour before you plan to have sex (depending on the specific medication). This makes them a convenient, easy-to-use choice for treating ED.

Here’s how quickly the four FDA-approved PDE5 inhibitors for ED work:

• Sildenafil. As mentioned, sildenafil typically starts working within 30 minutes to an hour and provides relief from ED for up to four hours per dose.

• Tadalafil. The active ingredient in Cialis, tadalafil, is a longer-lasting ED medication that can provide relief from ED symptoms for up to 36 hours per dose.

• Vardenafil. Vardenafil is similar to sildenafil and used to treat ED for five to seven hours per dose.

• Avanafil. Available as Stendra, this fast-acting ED medication works in 15 to 30 minutes and is less likely to cause certain side effects.

Get advice from a licensed healthcare provider to see if a prescription for ED medication is appropriate.

Other options for treating ED include medical devices, talk therapy (when a psychological issue causes ED), and lifestyle changes such as keeping yourself active, improving your diet, and limiting harmful habits like smoking and alcohol use.

We’ve talked about these approaches more in our detailed guide to the best ways to protect your erections naturally.

Erectile dysfunction is a frustrating issue that can develop at any time in life, from your 20s or 30s to older age. Is horny goat weed the solution? It might help, but it shouldn’t be your first choice.

Here’s what we know about horny goat weed versus Viagra for ED:

• Horny goat weed lacks sufficient research. For now, it’s not a reliable treatment for erectile dysfunction, whereas medications like Viagra have been extensively studied, proven effective, and FDA-approved to treat ED.

• Some animal studies are promising, but more human research is needed. While some animal studies suggest horny goat weed may improve blood flow and support erectile function, its safety and efficacy for humans remain uncertain. More research is needed to confirm its benefits.

• There are other options available. If you find it difficult to get or maintain an erection firm enough to have sex with your partner, consider exploring ED medication.

Learn more about ED medication and get advice from a healthcare professional to see if it can help.