Evening Primrose Oil for Missed Miscarriage

Evening primrose oil for cervical ripening

You may have already heard of misoprostol, a medication that is commonly given for missed miscarriage because it induces cervical ripening and labor. Evening primrose oil, when taken vaginally, has also been recognized in the research for its ability to induce cervical ripening. That’s because evening primrose oil contains linoleic acid and gamma-linoleic acid, which convert to prostaglandin. Prostaglandin has many roles in the body, but two of them include dilating the cervix and uterine contractions.

There has been some high quality evidence published in the last few years regarding evening primrose oil at the end of pregnancy for cervical ripening. It may be hard for you to read research involving evening primrose oil and pregnancy as you are going through a miscarriage, so we’re not going to take a deep dive on that right now. Let’s suffice it to say that the evidence shows that evening primrose oil administered vaginally shows promise for cervical ripening, but taking it orally is not effective.

If you are interested in more detail about the effects of evening primrose oil on cervical ripening, check out the first 2 citations down below.

Evening primrose oil for missed miscarriage

I used evening primrose oil for missed miscarriage at the recommendation of my provider. When I heard other women asking about options for missed miscarriage, I found some research articles specifically addressing the use of evening primrose oil for missed miscarriage. If you want to learn more about my experiences with missed miscarriage, D&C, misoprostol, evening primrose oil, and natural miscarriage, read more here.

The two randomized control trials that I was able to find both studied the use of evening primrose oil with misoprostol vs misoprostol alone. I wasn’t able to find any trials with the use of evening primrose oil alone. Here’s what the evidence shows:

Randomized control trial by Mahmoodinasab et al

148 women with missed miscarriage (mean gestational age 11 weeks) were divided into two groups. The intervention group used 2000 mg vaginal evening primrose capsules the night before the hospitalization, the control group did not use evening primrose oil. Both groups received misoprostol after hospital admission. In 5 of the women who used evening primrose oil, the process of miscarrying started with the evening primrose oil alone and they did not need misoprostol. This surprised the researchers, because they did not expect that evening primrose oil would be able to initiate miscarriage on its own. The researchers felt this was an area where future study is needed, as higher doses of evening primrose oil may have even better results.

Even in those women who did then go on to receive misoprostol, the outcomes were better in those who used evening primrose oil capsules. The use of evening primrose oil capsules resulted in more complete miscarriages. This means fewer people had retained products of conception, which would require additional doses of medication or a D&C. Women who used evening primrose oil also had less bleeding, and the miscarriage was completed in a shorter time. In both groups, pain scores were the same, and there was no change in length of hospitalization or side effects like nausea, diarrhea, headache, abdominal cramps, or fever.

Randomized triple-blind clinical trial by Hashemi et al

This study focused on women with missed miscarriage between 12-20 weeks gestation. 82 women were split into 2 groups. One group received a misoprostol tablet and 1000 mg of evening primrose oil capsules vaginally, while the other group had a misoprostol tablet and a placebo capsule. These were given together every 4 hours for up to 5 doses.

Researchers’ primary interest was the amount of time for the fetus to be expelled. This was significantly faster in the group who received evening primrose oil capsules. In the evening primrose oil group, 29 of the 42 women had passed the fetus in 4 hours or less. For the control (placebo) group, only 5 women had passed the fetus in 4 hours or less. The difference is even more striking if we look at the total number of women who passed the fetus in 8 hours or less. Only 47.5% of the women in the control group had passed the fetus, whereas 95.2% of the women in the evening primrose oil group.

There were other benefits to the evening primrose oil besides the reduced amount of time to pass the fetus. Women who used evening primrose oil capsules had lower pain scores, and fewer women needed curettage. 4.8% of women in the control group experienced side effects, and no side effects were reported in the group with evening primrose oil capsules. Researchers felt that this was due to lower amounts of misoprostol administered in the evening primrose oil group, as they more quickly passed the fetus and required fewer doses.

Summary of these studies on evening primrose oil for missed miscarriage

To summarize the results of these studies, for women with missed miscarriage, evening primrose oil shows promise on its own in initiating the miscarriage. Evening primrose oil also improved outcomes when used vaginally prior to misoprostol, or when used at the same time as misoprostol. This was true of women with missed miscarriages in both earlier and later stages of gestation.

I’ve found out I have a missed miscarriage. How do I use evening primrose oil?

You should use evening primrose oil capsules in whatever way your provider recommends. My provider recommended use of 2000 mg evening primrose oil capsules alone, and I used doses over multiple days per their recommendation while waiting for miscarriage to occur. Research has focused on the use of evening primrose oil capsules with misoprostol, with one study using 1000 mg capsules and the other using 2000 mg. Even with the different amounts of evening primrose oil and the differing timing, both studies showed good outcomes.

The key seems to be that evening primrose oil is effective when used vaginally. My provider recommended that I insert the evening primrose oil capsules right before bed, and this was the procedure followed in one of the first of the randomized clinical trials we reviewed as well.

Where to buy evening primrose oil

I found it difficult to find evening primrose oil capsules in stores near me. The VitaminShoppe had capsules but they were 1,300 mg, making it impossible to get the 2000 mg dose my provider was recommending. So ultimately I ended up buying evening primrose oil capsules online.

It is important when you are buying supplements to make sure you pick a good brand. Supplements don’t have the same regulation as a medication, and you want to be sure you are getting the right strength of ingredients. Herbal supplements aren’t regulated by the FDA, but there are organizations that assess supplements to determine if the manufacturing of the supplement is up to their standards. Look for a USP verified mark on supplements or some form of reliable 3rd party testing, and make sure they follow standards called Good Manufacturing Practices (GMP).

Safety of evening primrose oil

Overall, evening primrose oil is safe for most people for short term use. There are some risks and medication interactions, so taking evening primrose oil is something that you should always discuss with your medical provider.

Evening primrose oil could increase the risk of bleeding for those taking anticoagulant or antiplatelet medications or supplements. For people with epilepsy, taking evening primrose oil could increase the risk of seizure. Medication interactions can also occur with phenothiazine, a medication for schizophrenia and other psychotic disorders, which could cause a risk of seizures. 

Citations

1. https://evidencebasedbirth.com/evidence-on-evening-primrose-oil-epo/
2. Moradi M, Niazi A, Heydarian Miri H, Lopez V. The effect of evening primrose oil on labor induction and cervical ripening: A systematic review and meta-analysis. Phytother Res. 2021 Oct;35(10):5374-5383. doi: 10.1002/ptr.7147. Epub 2021 Apr 29. PMID: 33913585.
3. https://www.mayoclinic.org/drugs-supplements-evening-primrose/art-20364500
4. Nouri B, Baghestani A, Pooransari P. Evening primrose versus misoprostol for cervical dilatation before gynecologic surgeries; a double–blind randomized clinical trial. J Obstet Gynecol Cancer Res. 2021;6:87–94
5. Mahmoodinasab M, Loripoor M, Vazirinejad R, Aminzadeh F. Effect of misoprostol with and without evening primrose (Oenothera biennis) on induction of missed abortion. Avicenna J Phytomed. 2023 Sep-Oct;13(5):454-462. doi: 10.22038/AJP.2023.22179. PMID: 38089421; PMCID: PMC10711576.
6. Hashemi H, Hasanpoor-Azghady SB, Farahani M, Amiri-Farahani L. Comparison of the effect of vaginal misoprostol and evening primrose oil capsule with misoprostol alone on the consequences of abortion in women with intrauterine fetal death: a randomized clinical trial. BMC Complement Med Ther. 2023 Jul 19;23(1):248. doi: 10.1186/s12906-023-04082-w. PMID: 37468886; PMCID: PMC10354921.