Evening primrose (Oenothera biennis), sometimes called “the night willow herb,” is a flowering plant. It’s also a night owl, blooming at sunset instead of sunrise. The oil pressed from its seeds, aka evening primrose oil (EPO), is a gentle carrier oil.

EPO has a long history as a natural health remedy. It’s been hailed as everything from a hair loss solution to a cure for acne. It can be ingested, applied alone as a topical balm, or blended with other carrier oils for skin care formulations.

EPO’s good work is thanks to gamma-linolenic acid (GLA), an omega-6 fatty acid that reduces inflammation. Below, we dig into 13 science-supported perks of adding EPO to your daily routine.

Natural health and fertility sites often recommend EPO to accelerate babymaking. The idea is that the GLA in the oil improves cervical mucus and egg quality just like other omega fatty acids do.

A recent study also found that EPO can help treat polycystic ovary syndrome (PCOS), which is a common barrier to getting pregnant.

More research is needed, but if you’re trying to get pregnant, ask your doctor about EPO. Makes sense to add these healthy fats to your diet.

Hormone-related sweats and hot flashes are the worst, so we’re here for any science-backed remedies. EPO to the rescue!

A 2013 study found that menopausal women who took daily EPO supplements for 6 weeks reported fewer hot flashes — and the ones they did have were way less fiery. Even better? The women said cooling their hot flashes also improved lifestyle factors like social interactions and lovemaking.

That said, a recent review of all the current studies on EPO for menopause couldn’t find evidence that EPO reduces the frequency or severity of hot flashes. But the researchers noted some evidence for it soothing overall menopause symptoms.

Deal with breakouts on the reg? EPO could be your new BFF. The GLA ingredient soothes inflammation while the oil itself adds a dewy glow.

In one promising 2014 study, 45 people with acne had fewer lesions after taking GLA. Just keep in mind that the research sample is *super* small, so we need more studies to confirm this benefit.

Some research suggests EPO also soothes cheilitis, a swollen, red rash around your lips caused by isotretinoin (aka Accutane, a common anti-acne drug).

The research is thin, but EPO fans say it can soothe eczema or other skin irritation.

In one practically retro study (throwback to 1991!), researchers found that the GLA in EPO nourishes the top layer of skin, which gets inflamed by eczema.

And 2017 research on rats found that EPO (and even more so, EPO mixed with rosemary oil) helped relieve symptoms of eczema. Of course, animals are not people, so take this with a grain of salt.

Skin feeling a little “meh” these days? EPO’s healthy helping of GLA is known to improve elasticity, firmness, moisture — all the good stuff.

There are a couple of ways to use GLA for your complexion:

EPO supplements. A 2005 study suggests taking EPO boosts your body’s stores of skin-nourishing GLA (a fatty acid your skin can’t produce on its own). A 2011 study affirmed this when participants with dry skin noticed an improvement after noshing on GLA-rich foods.

Skin care formulations with EPO. A 2018 study found that moisturizing cream made from the ceramides in EPO helped skin maintain moisture and prevent water loss.

In a recent research review, experts found that oral intake of 4 grams or less of EPO per day could significantly increase levels of HDL (the good cholesterol) in blood. That’s good news for your heart.

Since heart disease is often linked to inflammation and cholesterol probs, EPO might indirectly reduce your risk of heart disease.

The jury’s still out on this one, but some research indicates that EPO could lower blood pressure.

A 2020 animal study suggests that EPO can reduce oxidative stress and help regulate cholesterol and systolic blood pressure. High blood pressure raises your risk of heart disease, so this is another vote for EPO’s heart-healthy powers.

There’s dated research that EPO could relieve PMS symptoms like irritability, moodiness, and even bloating. Again, it’s because of GLA, which triggers a chemical reaction that seems to prevent PMS.

A 2010 study further affirmed that supplements containing EPO (but also packed with vitamin B6 and vitamin E) helped with PMS. Of course, we don’t know whether the EPO or other vitamins deserve the credit.

Your emotions might not be the only thing that gets a little sensitive when the crimson tide rolls. If your boobs get achy on the reg, EPO could help.

Research suggests the GLA in EPO reduces inflammation, which causes PMS-related boob pain. And a 2017 study found that EPO is more effective than vitamin E at managing PMS symptoms like painful tatas.

TBH, not all studies come to the same conclusion about this — and some suggest that it takes several months to notice a difference — but in most cases, EPO has been more soothing than the placebo.

You already know the GLA in EPO is anti-inflammatory, which means it has the potential to soothe all kinds of aches — boob pain, joint pain, and so on.

In a large, double-blind clinical study, taking EPO supplements for 3 months reduced participants’ joint pain and inflammation.

A review of the research further backed up claims that a dose of EPO a day keeps arthritis away. Bonus — it didn’t seem to cause any side effects!

Health conditions like diabetes often come with an unhelpful side of nerve pain, tingling, weakness, and sensitivity to extreme temps. The good news is that GLA soothes damaged nerve symptoms.

In a 2014 study of 70 people with diabetes, participants who took EPO and vitamin E for a year experienced a reduction in nerve pain. Recent research suggests EPO could dial down that pain in as little as 3 months.

Whether you’re losing hair by the handful or are looking to give your locks a little extra “oomph,” EPO could help.

Research is still limited, but the arachidonic acid in EPO has been known to boost your hair growth potential. And again, GLA’s anti-inflammatory powers could help make your scalp a happier, healthier environment for your hair.

You’ll find EPO in heaps of weight loss supplements, but what does science say? Not much, TBH.

As you know by now, EPO contains GLA, which is an omega-3 fatty acid. Research suggests balancing your omega-3 and omega-6 intake reduces your risk of obesity. So yeah, in a way, keeping those fatty acids balanced is part of maintaining a healthy weight.

But claims beyond that just don’t hold weight (pun intended!). Even older studies suggest EPO doesn’t make a difference in weight loss efforts.

There’s been enough research on EPO to consider it generally safe for short-term use. But remember, supplements are a pretty unregulated industry. They don’t fall under FDA monitoring, so there could be issues with quality and dosing suggestions.

As for side effects, every rose has its thorn, right? Here are the most common:

If you’re allergic to other flowering plants or oils, be cautious about ingesting EPO. Watch for these signs of an allergic reaction:

  • swelling or redness in your hands or feet
  • rash
  • trouble breathing
  • whistling cough or other wheezing sounds

Seek medical attention ASAP if your reaction is severe.

Some folks recommend using EPO in the late stages of pregnancy to induce labor. That’s because it’s known to soften the cervix, which basically makes the pregnant person’s body ready to usher out le bébé.

That said, a 2018 study found no difference in the timing or duration of labor between women with full-term pregnancies who dosed on EPO for 7 days and the ones who didn’t.

While some older research (’90s, y’all) suggested that EPO could cause delivery complications, the U.S. Department of Health and Human Services says it “may be safe” for pregnant peeps.

Bottom line: We don’t know if it’s an effective or safe way to speed up labor. Your best bet is to talk with your doctor before popping EPO pills while preggo.

Evening primrose oil (EPO) has been used as a remedy for inflammation and several other skin and health conditions for years. More research is necessary to recommend it as a clinical treatment.

EPO combined with vitamin E could alleviate symptoms, but it shouldn’t replace meds recommended by your doctor.

Always use the lowest dose possible to reduce your risk of side effects. Talk with your doctor about the EPO method and dosage best for your specific health needs.