There aren’t any oils on the market that will make your penis larger. However, penis enlargement is possible through other measures.

There’s some evidence to suggest that vacuum pumps (sometimes just called penis pumps) and penile traction devices (or stretchers) can be effective.

But no research supports the idea that oils or other supplements will enlarge your penis. They’re much more likely to result in unwanted side effects or injury.

Read on to learn which oils you should avoid, which oils could improve your sexual function in other ways, and more.

Dietary and herbal supplements aren’t regulated by the U.S. Food and Drug Administration (FDA). This means that manufacturers are largely free to say whatever they want about their ingredients and supposed benefits.

In addition to being ineffective, these products may also be harmful. Many of the ingredients found in over-the-counter “natural male enhancement” supplements can cause unpleasant side effects and lead to potential complications.

You shouldn’t use any product containing:

  • Dehydroepiandrosterone (DHEA). DHEA is a steroid that naturally occurs in your body. But using DHEA supplements can increase your risk of cancer, lower good cholesterol levels, and affect your mental health.
  • Pregnanolone. This is another naturally occurring compound. But there’s no research to support pregnanolone for use in penis enlargement. It may also negatively affect your mental health.
  • Catuaba bark extract. This ingredient has shown some promise as an antidepressant, but no research indicates that it has any effect on your penis.
  • Hawthorn berry. This ingredient has some use as a treatment for heart disease, but it’s not proven to help with penis enlargement. Taking too much can cause dizziness, nausea, and dangerous interactions with cardiovascular medications.

Some ingredients can improve your sexual health — they just won’t make your penis bigger.

If you’re open to other benefits, look for an oil or supplement containing:

  • L-arginine. Older research suggests that this amino acid can reduce erectile dysfunction (ED) symptoms and make your erections firmer, but the jury’s out on how effective it truly is. Some research suggests it’s no better than a placebo.
  • Panax ginseng. This herb is thought to improve erectile response in people with ED by relaxing certain muscles around the penile tissues. A recent study validates ginseng as a safe, effective method of improving erection hardness.
  • Citrulline. This organic compound has been found to be a reliable treatment for mild-to-moderate cases of ED by making erections firmer.
  • L-carnitine. L-carnitine is known to help increase your sperm count, as well as sperm motility. This can improve your chances of getting your partner pregnant.
  • Gingko biloba. A study conducted on women found that gingko biloba may help with sexual arousal by stimulating blood flow and improving sexual function. This effect primarily occurred when participants combined supplementation with sex therapy.

Always talk to your doctor before using any oils or other supplements. Oil ingredients can interact with medications, have uncomfortable side effects, or increase your risk of certain conditions.

Once your doctor clears you to use an oil on your penis, do a patch test. To do this:

  • Rub a small amount of oil into your forearm.
  • Cover the area with a bandage.
  • Wait 24 hours and check for irritation. If you aren’t experiencing any redness, swelling, or other irritation, it should be safe to apply elsewhere.

If you pass the patch test, follow the oil’s application instructions closely. Only apply as much as the label advises, and keep the substance away from your urinary opening. Don’t apply more than the label directs.

Most importantly, don’t introduce oils into your sex life without asking your partner’s consent first. The oil can expose them to potential allergies and side effects, too. If possible, have them do a patch test before you decide to do a full application.

If you or your partner begin experiencing any unusual symptoms, discontinue use and seek medical attention.

Because these oils aren’t regulated, you never really know what ingredients they contain and in what quantities. Not all supplements are unsafe, but uncomfortable and even permanent side effects are possible.

Some side effects are mild, including:

  • skin irritation
  • rash or bumps
  • fluid-filled blisters
  • itching or burning at the application site

These effects may go away a few hours or days after you stop using oils.

If you keep using the oils, these side effects can get worse or progress into more serious symptoms, including:

  • hives
  • pus or discharge from blisters or rash
  • infections in broken skin from scratching, which can also make you more susceptible to sexually transmitted infections (STIs)

If left untreated, these symptoms can lead to permanent scarring or damage to your penis.

Anaphylaxis, a life-threatening allergic reaction, is also possible. You should seek emergency medical attention if you have difficulty breathing, severe pain, or severe swelling.

Your partner can also experience these side effects if they’re allergic to any of the oil’s ingredients.

Some oils also break down the ingredients in latex condoms, many of which aren’t designed to be resistant to certain oil lubrication. This can increase your risk of STI transmission or unwanted pregnancy.

Side effects can become even more painful or life-threatening if the oil gets directly into the vagina, anus, or mouth.

Talk to your doctor before using any kind of oil, herb, or other supplements. Your doctor can discuss your individual risk of side effects and interactions, as well offer advice on proven methods of enlargement.

If you do decide to use an oil, make sure you do a patch test. You should make sure it’s okay with your partner and talk to them about doing a patch test of their own.

Discontinue use if you or your partner begin experiencing symptoms.

Seek emergency medical attention if you experience any major symptoms after use, such as severe hives or difficulty breathing.