Erectile dysfunction (ED) can stir up a lot of emotions in the men who experience it, such as anxiety, shame, and low self-esteem. These feelings may make it difficult to speak up and get help. For example, 43 percent of our 600 survey respondents admitted they waited years before seeking professional ED treatment. Over one-third said they initially tried over-the-counter (OTC) ED supplements—a strategy that Jonathan Davila, a urologist at Northwell Health of Staten Island in New York, says can be risky and expensive. 

“Some men are in denial about their erectile dysfunction,” says Davila. “They feel they are just missing a certain nutrient from their diet.” 

It’s important to note that certain supplements for ED can work for some men, but not all ED supplements are created equal. Many of these products claim to boost the body’s natural production of testosterone or nitric oxide—two neurotransmitters essential for the development of an erection. However, none of these claims are regulated by the FDA, and research has shown that the currently available literature reviewing the efficacy of OTC ED supplements is low quality and therefore more research is needed to determine whether these supplements actually work. 

The urologists we’ve interviewed tend to agree with that stance. “There’s anecdotal evidence behind a lot of them, but their safety and efficacy have not been thoroughly vetted,” says urologist Wesley Yip. On the other hand, naturopathic doctors—licensed practitioners who take a more holistic and individualized approach to health—say some herbs, vitamins, and amino acids can improve men’s sexual health when taken under the guidance of a professional. 

To learn more about the potential benefits and risks of ED supplements, we spoke with Hannibal Miles, a naturopathic doctor based in New York City and Stamford, Connecticut. Although he’s seen first-hand how supplements can help with ED, he also advises people to be cautious. 

“Some people may not realize that herbs act like drugs. So if you’re taking other prescription drugs, you can enhance or amplify the effect of another drug that you might not necessarily want,” MIles says.

That’s why it’s important to talk to a health care provider before starting any ED supplements—you don’t want to risk your health or waste your money trying something that isn’t appropriate for you. To help you prepare for your next doctor visit, we explain the science behind ED supplements below.


Before you start using supplements to improve ED symptoms, talk to a health care provider. Herbs, vitamins, and amino acids can be dangerous based on your health history and current medications.

HelpGuide Handbook’s erectile dysfunction testing methodology

To research over-the-counter (OTC) supplements for erectile dysfunction, the Handbook Team interviews Hannibal Miles, a New York City-based naturopathic doctor experienced in treating ED with supplements. We also interview traditional urologists about the safety of prescription ED pills and the use of herbs during treatment. In addition, our team reads dozens of studies that test the efficacy of specific ingredients for treating ED.

The team also held multiple focus groups with real users to get more candid responses about the effects of erectile dysfunction treatment.

The Handbook for erectile dysfunction supplements

ED Supplements
Talk to your doctor before starting supplements to avoid dangerous interactions and side effects. Talk to your doctor before starting supplements to avoid dangerous interactions and side effects.
ED supplements primarily work by boosting testosterone or nitric oxide (NO) production. ED supplements primarily work by boosting testosterone or nitric oxide (NO) production.
The underlying cause and severity of your ED affects how well supplements may work. The underlying cause and severity of your ED affects how well supplements may work.
Look for the GMP or cGMP seal to confirm safe manufacturing practices. Look for the GMP or cGMP seal to confirm safe manufacturing practices.

Nitric oxide boosters 

Nitric oxide (NO) is the main neurotransmitter responsible for an erection. It sparks the chemical reaction that ultimately causes the penile blood vessels to widen, resulting in increased blood flow to the penis and an erection. Insufficient NO production is believed to be a major cause of erectile dysfunction.

The body gets NO by:

  • Breaking down the amino acids L-citrulline and L-arginine.
  • Extracting NO from food with the help of gut bacteria.
  • Receiving NO directly through pharmaceuticals known as NO donors (e.g., nitroglycerin).

A medical professional must oversee the use of NO donors, but dietary supplements provide NO through the other two channels. 

“Most people think of L-arginine for ED, which is good. But I prefer its counterpart, L-citrulline,” says Miles. “If people have a lower immune system, viruses sometimes feed on arginine.”

Beetroot powder and red spinach powder are other potential sources of NO, but you’ll get the most benefit if your gut bacteria are healthy. Consider taking probiotics simultaneously to ensure you have sufficient “good” bacteria to release the NO. Miles warns that these powders must be taken long-term to produce results, and that eating whole beets or spinach leaves won’t give the same effect as consuming concentrated powders.

Vitamin B6 is an important cofactor in NO production, says Miles, so you should also make sure you don’t have a B6 deficiency. Nitric oxide supplements often include B6 for this reason. Studies show vitamin C and Panax ginseng also aid in the production of nitric oxide. However, Panax ginseng may be dangerous for people taking medications that treat high blood pressure and diabetes, among others. Talk to your health care provider before starting a nitric oxide supplement.

Testosterone boosters 

Low testosterone (T) is the underlying cause of ED in about 5–18 percent of men with erectile dysfunction. Testosterone replacement therapy (TRT) is one option for increasing erectile function and libido, but it has some disadvantages. Injecting testosterone into the body rather than stimulating its natural production can actually lower sperm count and shrink the testes

On the other hand, testosterone-boosting supplements prompt the body to make more T, which helps to keep supporting hormones like luteinizing hormone—the one responsible for testes size and sperm count—in balance too. Still, taking testosterone boosters doesn’t guarantee an improvement in ED, especially if your ED isn’t caused by low T to begin with.

“Testosterone has a wide variety of effects,” says Miles. “Theoretically it should help, but it may be helping because you’re more sexually aroused. It’s not necessarily a direct biochemical effect.”

Popular testosterone-boosting herbs include:

  • Tongkat Ali (Eurycoma longifolia).
  • Yohimbe (Pausinystalia johimbe).
  • Fenugreek (Trigonella foenum-graecum).
  • Ashwagandha (Withania somnifera).
  • Asian ginseng (Panax ginseng).
  • Horny goat weed (Epimedium sp.).
  • Puncture vine (Tribulus terrestris).
  • Maritime pine (Pinus pinaster).
  • Maca (Lepidium meyenii).

Each one can cause different side effects, drug interactions, or allergic reactions, and the effects can build when the herbs are combined. Play it safe and talk to a health care provider before taking a testosterone booster. 

Other popular ingredients—like diindolylmethane (DIM) and boron—increase the amount of “free” T in the bloodstream, where it participates in the chemical reactions that cause an erection. Testosterone boosters may also contain vitamins and minerals that support T production, such as vitamin B3 (niacin), vitamin D3, and zinc.

Miles recommends being patient if you take testosterone boosters because their effects build over time, requiring a long-term commitment. He also suggests getting your testosterone levels checked before taking a supplement. If your testosterone is already in a healthy range, testosterone boosters are unlikely to improve ED. Testosterone supplements should not be taken by men with hormone-sensitive benign prostatic hyperplasia (BPH).

“Natural Viagra”

Icariin is a PDE5 inhibitor (like Viagra and Cialis) that’s naturally found in horny goat weed. In animal studies, icariin has shown promise as an ED treatment when the underlying cause is poor blood flow, but it isn’t as powerful as sildenafil (Viagra) or tadalafil (Cialis)

Icariin hasn’t been studied much in humans, but researchers have found that rats need about 10 milligrams of icariin per kilogram of body weight for improved erectile function. Another study found that up to 100 mg/kg of icariin continued to have positive effects on the rats by boosting testosterone and sperm count.


Horny goat weed shouldn’t be taken by people with estrogen-sensitive cancers. Horny goat weed may cause slow blood clotting, breathing problems, or low blood pressure in some people, as well as increased anxiety when consumed with caffeine. If you take medications processed through the liver, talk to your doctor before taking horny goat weed.

Following the FDA’s guidelines for estimating safe starting doses in healthy adults based on animal trials, this 10–100 mg/kg range translates to about 110–1,098 mg for a 150-pound man and 182–1,829 mg for a 250-pound man. Unfortunately, the Handbook Team found many horny goat weed supplements have an icariin content that’s far lower than the amount believed to be therapeutic. Some supplement brands don’t disclose the amount of icariin at all.

Vitamins and minerals that support sexual function

The body requires certain vitamins and minerals in order to produce testosterone. According to Miles, these essential ingredients (also called cofactors) include:

But producing enough testosterone is just one step toward improving erectile health. For best results, testosterone also needs to be “bioavailable,” or freely circulating and ready to interact with other molecules. Free testosterone, for example, plays a role in increasing NO and decreasing PDE5—two essential processes for developing an erection. Improving testosterone’s bioavailability requires minerals like folate and magnesium.

A well-formulated men’s multivitamin helps avoid deficiencies that could decrease testosterone production or reduce testosterone bioavailability. There are plenty of options on the market. Consider one without iron, which can reduce testosterone production when taken in excess.

If you haven’t been checked recently for vitamin deficiencies, consider getting your bloodwork done. Your doctor may recommend higher doses of specific vitamins based on the results.

Our research experience 

Herbs have been used in traditional medicine throughout the world for thousands of years, but their healing properties aren’t often studied by modern scientists. That may explain why the urologists we spoke with had little experience recommending ED supplements to their patients. Herbs—which make up the most common ingredients in ED supplements—typically don’t fall into a urologist’s area of expertise.

To get a more balanced perspective on whether supplements could work for men with ED, we talked to someone who does use herbs to heal his patients: Hannibal Miles. Miles sat down with us via Zoom and explained why some people prefer supplements versus prescriptions, how to choose safe supplements, what ingredients he recommends to patients with ED, what secondary ingredients are necessary for best results, and the risks associated with supplements.

Next, we read research studies that support the information Miles shared with us. We also read a number of journal articles that report inconclusive results regarding the use of natural supplements for ED. The one thing everyone can agree on is that you should talk to a medical professional before taking a supplement. They can determine whether the ingredients pose a risk to you based on your health status, medical history, and medications or supplements you’re currently taking.

Pros and Cons of ED Supplements 

Supplements may work where traditional treatments have failed. “People come to me, or to a naturopathic doctor in general, when they try the traditional system for a while and it’s not working for them,” says Miles. He says that Western medicine tends to cover up the symptoms of a chronic condition rather than heal the root cause. Supplements are just one tool naturopathic doctors may use to treat their patients.

ED supplements don’t work quickly. Don’t expect same-day results with an ED supplement. Miles says the effects of herbal supplements build over time, so it’s important to take them consistently and as directed.

Their effectiveness depends on the root cause of your ED. Erectile dysfunction supplements won’t work if your ED isn’t related to poor blood flow or low testosterone. ED related to anxiety or nerve damage, for example, requires a different treatment.

Urologist Jonathan Davila advises men with erectile dysfunction to seek medical advice rather than use supplements. “Corporations know how vulnerable men with ED are, and they take advantage of them by charging obscene prices for a mix of basic amino acids, vitamins, and other random ingredients,” says Davila.

You need to watch for side effects and contraindications. Herbs, vitamins, and amino acids can produce adverse side effects in some people. They can also interact with other herbs or medications, sometimes to a dangerous degree.

“I find it interesting that the ingredients in most of these supplements are reportedly unsafe to take if patients are on hypertensive or diabetic medications,” says Davila. “The reason is that about 75–90 percent of men with erectile dysfunction have diabetes, hypertension, or metabolic syndrome, which would mean that a majority of patients with ED should not be taking these supplements.” 

Unscrupulous manufacturers may include hidden ingredients. The FDA has found hidden sildenafil (generic Viagra) in over-the-counter ED pills. This poses a danger to people who can’t take sildenafil due to intolerable side effects, contraindicated medical conditions, or potential drug interactions.

“It’s difficult as a physician to endorse these products without having any reservations,” says Davila. “I always tell patients that they would be taking them at their own expense and risk.” 

Are ED supplements safe? 

The safety of an ED supplement depends on the product and the person taking it. The best thing to do is to consult a doctor before taking a new supplement. Even “all-natural” products can produce unwanted side effects. A doctor can review your medical history and current medications to decide if a supplement’s potential benefit outweighs its potential risk.

Look for the cGMP (or GMP) seal to confirm safe manufacturing practices. GMP stands for “good manufacturing process” and refers to the regulations outlined in the Federal Food, Drug, and Cosmetics Act. When products bear a cGMP seal on their labels, it means the manufacturers have met certain quality standards required by the government. 

Our final verdict

Most ED supplements work by improving your body’s ability to produce nitric oxide and testosterone. If your ED is caused by low testosterone or poor blood flow, these supplements may address the root of the problem and lead to better erections over time.

Despite their natural ingredients and OTC availability, supplements aren’t inherently safe for everyone. Get your doctor’s approval before beginning a supplement regimen. Even if your doctor prefers a more traditional approach to treating ED, they can at least tell you whether a supplement poses a risk to your health.

Frequently asked questions

To an extent, yes. Some vitamins and supplements can support erectile health by increasing nitric oxide and testosterone production, but they’re not effective in men who already produce plenty of nitric oxide and testosterone. Herbal supplements with horny goat weed may improve ED by inhibiting PDE5—a chemical that reduces blood flow to the penis and keeps it flaccid.

Research suggests there could be at least two natural alternatives to Viagra: saw palmetto extract and icariin, a compound derived from horny goat weed. Like sildenafil, which is the generic form of Viagra, they both inhibit a chemical called PDE5. However, saw palmetto extract and icariin have mostly been studied in rodents, so it’s unknown whether they’re truly effective in treating people with ED.

An ED treatment that’s safe and effective for one person may be unsafe or ineffective for another. Your overall health status, current medications, and drug and alcohol use can affect the safety of a prescription or over-the-counter treatment. To lower your risk of serious side effects when taking anything for ED, discuss your options with a health care provider.

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