Peptides for erectile dysfunction (ED): safety, efficacy, and more

If your social media feed has been flooded with ads for peptides for erectile dysfunction (ED), you may be wondering whether they actually work and how they compare to first-line treatments, such as Viagra and Cialis. Or maybe you’re just wondering: What are peptides, anyway?

The short answer on peptides for ED: It’s possible some peptides could help with ED, but the research is still emerging, and there’s a lot we don’t know. Unlike ED medications that are approved by the United States Food and Drug Administration (FDA), many peptide products aren’t well-regulated, and there are still lingering questions about their safety, effectiveness, and sourcing. 

Keep reading to find out what peptides are, the purported best peptides for erectile dysfunction, and alternatives to consider.

Peptides are short strings of amino acids — the building blocks of proteins — that interact with certain receptors and signaling pathways in the body. Some peptides are being studied for their potential effects on sexual function, though the research is limited. 

Unlike FDA-approved treatments like Viagra (sildenafil) and Cialis (tadalafil), which work by blocking the phosphodiesterase type 5 (PDE5) enzyme to increase blood flow to the penis, peptides may work through a completely different mechanism involving the brain, to influence arousal and desire.

One of the most popular peptides for ED  is the PT-141 peptide, also known as bremelanotide. It’s FDA-approved under the brand name Vyleesi as a subcutaneous injection to treat hypoactive sexual desire disorder in premenopausal women, though clinical trials have also studied this medication as a nasal spray for ED. 

Other peptides that have limited studies for ED include:

• Melanotan II: A peptide originally studied for tanning, melanotan II was later found to produce erections in some men through central brain pathways. While early studies showed promise for ED, side effects including significant nausea and limited research have prevented widespread use.

• Oxytocin: Sometimes called the “love hormone” because of its role in social bonding, oxytocin has also been studied for its potential role in sexual arousal, erectile function, and orgasm. However, most of the evidence comes from animal studies rather than human clinical trials. More research is needed to see whether oxytocin might be helpful for improving erections in humans. 

• Vasoactive intestinal peptide (VIP): Also known as aviptadil, VIP has been studied as part of a combination treatment called Invicorp, which is injected directly into the penis. Invicorp is not FDA-approved in the United States. Using VIP for ED is uncommon compared to first-line treatments for ED and is typically only considered when other options haven’t helped. 

• BZ371A: BZ371A is a newer topical peptide being studied for ED, especially in men recovering from prostate surgery. Early research suggests it may increase local nitric oxide production, though it’s still in clinical trials.

Researchers have also been exploring whether glucagon-like peptide-1 receptor agonists (aka GLP-1s like Ozempic and Foundayo) may indirectly improve erectile function through their effects on weight loss, blood sugar control, cardiovascular health, and testosterone levels, since all of these factors can play a role in ED. More long-term research is needed to determine the effects of these medications on erectile function over time. 

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Using peptides for ED is still considered experimental and isn’t recommended by experts at this point. But early research suggests they could affect pathways involved in sexual desire, arousal, and nerve signaling in the brain. 

Still, some experts caution that the evidence is limited and that growing interest in peptides may be outpacing the science. “The challenge is that the science has not really caught up with the marketing,” says Rajesh Patel, MD, a board-certified urologist and President of Associated Urological Specialists (AUS).

Dr. Patel says theories that certain peptides may improve blood flow or affect hormone pathways aren’t yet backed by strong clinical data in large groups of patients. “Right now, much of the excitement is being driven by smaller studies, anecdotal experiences, and social media, rather than high-level evidence.” 

Here’s what the current research says about how some of the most popular so-called ED peptides may work:

PT-141 (bremelanotide)

PT-141, or bremelanotide, is probably the most talked about peptide for erectile dysfunction, but how does it work? 

Studies show that bremelanotide works by activating central nervous system pathways involved in sexual desire and arousal. This is totally different from how PDE5 inhibitors like Viagra work. While PDE5 inhibitors like Viagra increase blood flow to the penis through pathways involving nitric oxide, bremelanotide acts mostly in the brain, which then affects the body. 

In some clinical studies, bremelanotide has been associated with both pro-erectile effects and increased sexual desire, though more research is needed. 

Some researchers have also explored whether PT-141 could help men who don’t respond to PDE5 inhibitors. In one study, some men who didn’t respond to sildenafil reported improved erections and more satisfaction after using a PT-141 nasal spray. So far, this nasal spray is not widely available and has not achieved FDA-approval for the treatment of ED. 

In another small study, some participants reported improvements in erectile function, sexual desire, and sexual satisfaction after using bremelanotide. However, the study only included 19 participants, there was no placebo for comparison, and the findings were based on self-reported outcomes. Adding to the limitations, the study was sponsored by the company behind Vyleesi.

Melanotan II

When you take a PDE5 inhibitor, sexual stimulation triggers increased blood flow to the penis with the help of the medication. But melanotan II behaves differently. It acts through the brain via pathways related to sexual arousal and, at times, it can initiate erections in men without any sexual stimulation. 

In small, placebo-controlled studies, some men reported erections and increased sexual desire after receiving melanotan II injections. However, side effects including significant nausea, yawning, and penile stretching, along with  a relatively slow onset of action, limited the peptide’s clinical usefulness. Melanotal II is not FDA-approved, and more research is needed on a larger scale to determine safety and effectiveness.

Vasoactive intestinal peptide (VIP)

VIP has been studied as an ED treatment, often in combination with other medications. One combination therapy is marketed as Invicorp. In one 2023 study, more than half of men who hadn’t found success with other ED treatments like PDE5 inhibitors reported that Invicorp was effective enough to have satisfying sex. It was also less painful than other injectables prescribed for ED.

However, Invicorp is not FDA-approved in the United States. Using VIP for ED is typically only considered when other options have failed.

At this point there’s not enough safety data to know if peptides are safe for ED. There are also no FDA-approved peptides for the treatment of erectile dysfunction, so their use is largely experimental.

Another concern is that many peptides are accessed through compounding pharmacies and online vendors, raising questions about the supply chain and manufacturing process. For example: What manufacturing standards are being followed?  Where are ingredients sourced from? Are the products pure, accurately dosed, and free from contaminants?

“Safety is probably my biggest concern,” Dr. Patel says. “Many of these peptides are not FDA-approved specifically for ED, and depending on where patients obtain them, there can be variability in quality and consistency.”

Side effects and risks of peptides for ED

Potential side effects vary depending peptide, dose, and delivery method, but studies on peptides for ED have linked them to side effects such as:

• Nausea

• Flushing

• Headaches

• Injection site reactions

• Vomiting

• Fatigue

• Temporary changes in blood pressure

• Yawning

• Spontaneous erections without sexual stimulation

Until more research confirms peptides are a safe and effective option for treating ED, experts recommend opting for research-backed, FDA-approved treatments instead. These include prescription medications, lifestyle changes, and more we’ll explore below. 

The most important thing is to see a qualified healthcare professional before starting any treatments for ED (especially unproven treatments like peptides) to rule out any other issues. 

“As a urologist, I would not recommend peptides as a first-line treatment for ED,” Dr. Patel says. “My approach has always been to first figure out why a patient is having erectile dysfunction. ED is often a symptom of something else going on — vascular disease, diabetes, obesity, low testosterone, medication effects, stress, or other health issues.”

Once you’ve ruled out a more serious issue, safer, proven alternatives to peptides for ED include:

Prescription ED medications

With a 60%–70% success rate, it’s no wonder PDE5 inhibitors like Viagra (sildenafil) and Cialis (tadalafil) are some of the most commonly prescribed medications for ED. 

These FDA-approved medications work by blocking an enzyme called PDE5, which helps the smooth muscle in the penis relax, allowing increased blood flow when you’re sexually aroused. This helps you get and maintain an erection. They’re also backed by significantly more safety and efficacy data than peptides.

ED medications have also evolved beyond the classic little blue pill. Today, some treatments come in alternative formulations, including Ro's Daily Rise Gummies (containing tadalafil), and fast-acting sublingual options like Ro Sparks (which contains both sildenafil and tadalafil). These are compounded formulations, which means they are custom-prepared using FDA-approved active ingredients, but the specific combination products themselves are not FDA-approved for the treatment of ED. 

Lifestyle changes

In some cases, making healthy lifestyle changes may also help with erectile function. Lifestyle modifications that have been shown to improve ED include:  

• Regular physical activity

• Maintaining a healthy weight

• Eating a balanced diet rich in fruits, vegetables, and whole grains

• Quitting smoking

• Limiting excessive alcohol consumption

• Managing stress

• Prioritizing quality sleep

Testosterone replacement therapy

Low testosterone can sometimes contribute to ED and low libido. For men with clinically low testosterone levels, testosterone replacement therapy (TRT) may help improve symptoms. That being said, testosterone replacement therapy is  not appropriate or effective for every cause of ED and it comes with risks so you should discuss with your healthcare provider to see if it’s appropriate for your specific situation.

Psychotherapy

Some men have trouble getting or maintaining an erection due to psychological factors like performance anxiety, depression, stress, or relationship problems. In some cases, medications used to treat mental health conditions may also contribute to sexual problems. 

Research suggests therapy approaches like cognitive behavioral therapy (CBT) and sex therapy may help improve erectile function in some men, particularly when psychological factors are involved. In some cases, combining therapy with medication may work better than medication alone.

Vacuum erection devices

Also known as penis pumps, vacuum erection devices create suction around the penis to help draw blood into the area and produce an erection. They may be an option for people who can’t take oral ED medications or prefer non-drug treatments. Satisfaction rates with this method vary widely, so this method may not be right for everyone.

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Peptides may be trending, but researchers are still working to better understand how effective and safe these treatments are for ED. Until we know more, here’s what to consider: 

• Research on peptides for ED is still limited. Most studies have been small, short-term, or focused on specific groups of patients, making it hard to draw clear conclusions about the long-term safety and effectiveness of peptides for ED.

• PT-141, or bremelanotide, is one of the most studied peptides for ED so far. Early research suggests it may help support erections and sexual desire by activating pathways involving the nervous system and nitric oxide production. More research is needed, though.

• Peptides aren’t risk-free. Reported side effects have included nausea, flushing, headaches, yawning, spontaneous erections, and temporary changes in blood pressure.

• FDA-approved ED medications remain a first-line treatment. Treatments like Viagra and Cialis are backed by far more clinical research and long-term safety data than peptides for ED.

• Speak with your healthcare provider. If you have ED, it’s important to rule out more serious causes that could contribute to sexual dysfunction. Avoid purchasing unproven treatments from unregulated sources, because product quality and safety cannot be guaranteed.