Does fish oil help sexually? 4 benefits science supports

You've probably seen fish oil recommended for just about everything: heart health, brain function, joint support. But does fish oil help sexually?

It might help, but it's not a proven fix. Early research links omega-3 fatty acids, the key nutrients in fish oil, to better blood flow, healthier testosterone levels, and improved sperm quality. That said, we're not quite at the point of calling fish oil a sexual health treatment. Keep reading to learn what science says about fish oil benefits for men. 

Fish oil may be best known for supporting heart health, but it could also play a role between the sheets. Here are four sexual benefits of fish oil that have some science behind them.

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1. Helps support erectile function

Getting and maintaining an erection depends on healthy blood flow, and this is where fish oil may play a role. The omega-3 fatty acids in fish oil may stimulate the production of nitric oxide, a molecule that helps blood vessels relax and widen. Prescription erectile dysfunction (ED) medications support this same pathway, though they work differently.

Omega-3s can also reduce inflammation in blood vessel walls, which may improve circulation overall.

Animal studies support this connection. Rats with ED caused by clogged arteries showed improved erection quality after receiving omega-3 fatty acids. Of course, animal studies don't always translate to humans.

So, does omega-3 help sexually? The vascular benefits are real and well-established contributors to erectile health, but direct human trials on omega-3s and ED are still lacking. More research is needed before we can say for sure.

2. Supports healthy testosterone levels

Testosterone plays a central role in sex drive, erections, and overall sexual function. 

In a secondary analysis of a small 2020 trial, 22 men with overweight or obesity were studied for 12 weeks. Those who took docosahexaenoic acid (DHA)-enriched fish oil supplements ended up showing an increase in testosterone levels. The finding is preliminary but worth following. It aligns with a much larger study of nearly 1,700 young Danish men, which found that fish oil supplement users had hormonal markers consistent with healthier testicular function, including a higher free testosterone-to-luteinizing hormone (LH) ratio and lower FSH/LH levels.

More recently, a 2024 study found a link between fish intake and higher testosterone levels in older men. However, the link was strongest for lean fish specifically.

That said, does fish oil increase testosterone enough to treat clinically diagnosed low testosterone? Probably not on its own. 

If you're dealing with symptoms of low testosterone, a healthcare provider may suggest additional testing. If you do end up having clinically significant low testosterone levels, they may suggest treatments like testosterone replacement therapy (TRT). But fish oil could be a worthwhile addition to a broader healthy lifestyle approach.

3. May improve fertility and sperm quality

If you're thinking about starting a family, or just curious about reproductive health, this one's worth paying attention to. 

In a large Danish study, young men who took fish oil had higher semen volume and total sperm count. They also had better levels of reproductive hormones that help regulate sperm production.

So, does fish oil increase testicle size? The same study found that those who took fish oil supplements had larger testicular volume compared to non-users. This is likely related to improved testicular function overall, though the study couldn't confirm that fish oil was the direct cause.

DHA, one of the key omega-3 fatty acids in fish oil, is a structural component of sperm cell membranes. It plays a role in helping sperm penetrate an egg, a process known as the acrosome reaction. Omega-3s may also reduce oxidative stress and inflammation, both of which can negatively affect sperm health.

4. Supports mood and libido

Sexual desire doesn't just happen below the belt; it starts in the brain. Depression and anxiety can lower libido and affect sexual function. There's some evidence that omega-3s may help here.

Some meta-analyses suggest that omega-3 supplements may modestly reduce depression symptoms, particularly Eicosapentaenoic acid (EPA)-heavy formulas. The connection to sexual health is indirect and needs more evidence behind it, but if low mood is getting in the way of your sex life, it doesn’t hurt to try omega-3s. 

The sexual benefits are just one piece of the puzzle when it comes to what fish oil does for men. Omega-3s may also support your health in a few other key ways.

For your heart, omega-3s may help lower triglyceride levels and support cardiovascular function overall. At higher doses (2 grams per day or more), they may also modestly reduce blood pressure, especially in those with high blood pressure or high cholesterol. This ties directly back to sexual health, too — the same blood vessels that serve your heart also support erections.

There's also some evidence that omega-3s may support cognitive function as you age, though research is mixed. And fish oil may play a role in eye health, with research linking omega-3 intake to a reduced risk of dry eye disease and age-related macular degeneration.

The main differences between fish oil and cod liver oil are where they come from and what extra nutrients they contain. 

Fish oil is derived from fatty fish, such as salmon, mackerel, and sardines. Cod liver oil, as the name suggests, comes specifically from the liver of cod. And because the liver is where fish store many fat-soluble vitamins, cod liver oil is naturally rich in vitamins A and D.

Both contain omega-3 fatty acids, specifically EPA and DHA, the two types your body uses most easily. Your body can't produce these essential fatty acids on its own, which is why they should come from food or supplements. 

Regular fish oil typically contains only omega-3s, not the extra vitamins. So, it can be worth checking the label if you're looking for vitamins A and D, too.

When it comes to cod liver oil benefits for men, the added vitamin A and vitamin D can support immune function, bone health, and overall wellbeing. However, most of the sexual health research has focused on omega-3 fatty acids broadly, with more limited research on cod liver oil specifically.

Either option can help boost your omega-3 intake. So how do you make sure you're getting enough?

There are two main ways to increase your omega-3 intake: food and supplements.

The best dietary sources of EPA and DHA are fatty fish: salmon, mackerel, sardines, herring, and anchovies. The American Heart Association recommends eating 1–2 servings of fish per week, preferably oily fish.

Plant-based sources such as flaxseed, chia seeds, and walnuts provide a different type of omega-3 called alpha-linolenic acid (ALA), which your body converts to EPA and DHA less efficiently.

If you don't eat much fish, a fish oil supplement can help fill the gap. Most health organizations recommend 250–500 mg of combined EPA and DHA per day for general health. 

When choosing a supplement, look for one that lists the amounts of EPA and DHA on the label, not just total fish oil. A product that's been third-party tested for purity is a good bet. This is especially because supplements are not regulated by the US Food and Drug Administration (FDA). 

Before you start supplementing, though, there are a few things to keep in mind.

Fish oil is generally well-tolerated, but it can cause some minor side effects. The most common complaints include a fishy aftertaste, burping, and mild digestive issues like nausea or diarrhea.

At higher doses (2 grams per day or more), fish oil may slightly increase the risk of bleeding. This is particularly important if you're taking blood thinners or other medications that affect clotting. 

High-dose omega-3 supplementation, typically above 2 grams per day, has also been linked to a slightly higher risk of atrial fibrillation (a common heart rhythm disorder) in some studies. This risk appears dose-dependent.

Cod liver’s vitamin A content can also add up quickly, especially if you’re also taking a multivitamin or eating fortified foods. Too much intake of pre-formed vitamin A can harm the liver, so make sure to stay under the recommended daily limit. 

As with any supplement, it's a good idea to talk with a healthcare provider before starting fish oil, especially if you take medications or have an existing health condition. Supplements are not as regulated by the FDA as prescription medications, and if sexual health is your main concern, it's worth knowing what FDA-approved medication options are available.

Fish oil may offer some supportive benefits for sexual health, but it's not a substitute for clinically proven prescription ED treatments. PDE5 inhibitors are commonly prescribed medications to enhance blood flow to the penis and help with erections.

Options include:

• Sildenafil (Viagra)

• Tadalafil (Cialis)

• Vardenafil (formerly available as brand-name Levitra, now available as generic)

• Avanafil (Stendra)

You should discuss whether these options may be safe for you to try with a healthcare provider (such as one on Ro). If you have any other medical conditions or are taking other prescription medications, be sure to tell your provider. 

Ro also offers two unique treatment options. Ro Sparks* is a fast-acting option made with sildenafil and tadalafil that can work in 15 minutes (after dissolving) and last up to 36 hours. Daily Rise Gummies* are a daily tadalafil gummy that works continuously, no planning or timing required.

*Though this particular formulation is not FDA-approved, it is composed of active ingredients that have been FDA-approved for ED.

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So, does fish oil help sexually? It shows some promise, but it's not a guaranteed fix. Here's what to keep in mind:

• Omega-3 fatty acids may support vascular health and improve circulation, both of which matter for erectile function. But human research on fish oil and ED specifically is still limited.

• The research on fish oil, testosterone, and fertility looks promising, but most of it is observational. More clinical trials are needed before fish oil can be called a reproductive health tool.

• Fish oil can be a solid addition to a healthy lifestyle. However, it's not a substitute for proven treatments. If you're dealing with ED or other sexual health concerns, a healthcare provider (such as one on Ro) can help you find an approach that works.