Evening primrose oil contains gamma-linolenic acid (GLA), an essential fatty acid in the omega-6 family of oils that is metabolized to dihomogammalinolenic acid (DGLA). These fatty acids are precursors to prostaglandins series 1 and 2 (PGE1 and PGE2).  Evening primrose oil contains about 4 to 16 % GLA while borage oil has about 22% and black currant seed oil has about 17%. Evening primrose oil has a high concentration of linoleic acid.

My opinion at this time is that I prefer using fish oils or krill oil for anti-inflammatory purposes than primrose oil.
       
Evening Primrose Oil benefit and research review by Ray Sahelian, M.D.
Evening primrose oil has antioxidant and anti-inflammatory properties.
This product has shown inconsistent results in the treatment of atopic dermatitis and other medical conditions.
Neither fish oils or evening primrose oil have been found to be helpful in reducing mastalgia (breast pain).

Acne in those treated with medication
Ann Dermatol. 2014. The effect of evening primrose oil for the prevention of xerotic cheilitis in acne patients being treated with isotretinoin: a pilot study. The most common adverse effects of oral isotretinoin are cheilitis, skin dryness, dry eyes, and conjunctivitis, whereas evening primrose oil (EPO) is known to improve skin moisture and transepidermal water loss (TEWL) in healthy adults and atopic patients. To evaluate the clinical efficacy and safety of EPO in preventing xerotic cheilitis in acne patients being treated with oral isotretinoin. Forty Korean volunteers of Fitzpatrick skin types III and IV, having moderate acne, were enrolled and randomized to receive either isotretinoin with or without EPO for 8 weeks. The efficacy of treatment was evaluated on the basis of global acne grading system scores, number of inflammatory and noninflammatory lesions, TEWL, corneometry, physician's global assessment, and patient satisfaction. The results after 8 weeks of treatment showed that the TEWL of the lip increased significantly during isotretinoin treatment, whereas the TEWL of the hand dorsum showed no significant change. The increase of the TEWL of the lip was more definite in the control group than in the experimental group. The number of acne lesions decreased significantly in both groups, and there were no differences between them. Our study suggests that the addition of EPO improved xerotic cheilitis in acne patients being treated with oral isotretinoin.

Anti-inflammatory
Long-chain fatty alcohols from evening primrose oil inhibit the inflammatory response in murine peritoneal macrophages. J Ethnopharmacol. 2014 Jan 10.

ADHD
I was told by a doctor that they use to prescribe EPO for hyperactive children to help calm them down especially at night so they can sleep through the night. Is it of any help in this situation.
   I have not seen convincing studies with evening primrose oil being effective for the treatment of ADHD.

I read on your EPO page that you were unaware of studies for calming hyperactive children, but found these while googling, and thought you might be interested:
Double-blind administration of evening primrose oil to a subgroup of prior study was associated with improved parent ratings for Attention and Excess Motor Activity compared to placebo. (J Abn Child Psychol 1987).
Evening Primrose oil (GLA) 1 gram/day improved 53 of 79 hyperactive children selected as a subgroup on the basis of mood swings. The most striking improvement was noted in children with sleep disorders, crying spells and family history of alcohol or bipolar. (Muriel Blackburn, Crawley Hospital, Sussex , U.K.)

Atopic dermatitis
Adv Ther. 2014 Feb. Gamma-linolenic Acid levels correlate with clinical efficacy of evening primrose oil in patients with atopic dermatitis. Evening primrose oil (EPO) contains high amounts of GLA. Therefore, this study investigated whether EPO supplementation results in an increase in plasma GLA and its metabolite dihomo-gamma-linolenic acid (DGLA) correlating with clinical improvement of AD, assessed by the SCORing Atopic Dermatitis (SCORAD) index. The open study included 21 patients with AD. EPO (4-6 g) was administered daily for 12 weeks. Before treatment, and 4 and 12 weeks after initiation of EPO supplementation, objective SCORAD was assessed and plasma concentrations of GLA and DGLA were determined by gas chromatography. A significant increase in plasma GLA and DGLA levels and a decrease in the objective SCORAD were observed 4 and 12 weeks after initiation of EPO treatment. In the per-protocol population, a significant inverse correlation between the changes in plasma GLA levels and SCORAD was found. The clinical disease activity under EPO treatment correlates with the individual increase in plasma GLA levels. Thus, the results of this pilot study indicate that an increase in plasma GLA might be used as predictive parameter for responsiveness of AD to EPO therapy.

Breast tissue
We will update this site regarding the role of evening primrose oil and any effect on a woman's breast if we come across such studies.

Fibroadenoma
Effect of evening primrose oil on clinically diagnosed fibroadenomas.
Breast. 2000.
The effects of oil of evening primrose oil on fibroadenomas was assessed over a 6-month period. Eleven out of 21 (52%) of fibroadenomas receiving evening primrose oil and 8 out of 19 (42%) controls reduced in size. This study demonstrates that evening primrose oil does not significantly effect the natural history of breast fibroadenomas.

Mastalgia
Evening primrose oil and fish oil for severe chronic mastalgia: a randomized, double-blind, controlled trial.
Am J Obstet Gynecol. 2002.
The purpose of this study was to evaluate the effect of evening primrose oil and fish oil on breast pain in premenopausal women with severe chronic mastalgia, in a randomized double-blind factorial clinical trial. One hundred twenty women were placed randomly into four groups: (1) fish oil and control oil, (2) evening primrose oil and control oil, (3) fish and evening primrose oils, or (4) both control oils during 6 months. Corn oil and corn oil with wheat germ oil were used as control oils. The change in the percentage of days with breast pain after 6 months of treatment was analyzed on an intention-to-treat basis. The decrease in days with pain was 12.3 % for evening primrose oil and 13% for its control oil; the decrease in days with pain was 15% for fish oil and 10% for its control oil. All groups showed a decrease in pain. Neither evening primrose oil nor fish oil offered clear benefit over control oils in the treatment of mastalgia.

Evening Primrose Oil side effects, safety
No significant side effects have been reported with evening primrose oil when ingested in reasonable amounts.

The safety of evening primrose oil in epilepsy.
Prostaglandins Leukot Essent Fatty Acids. 2007.
Not only are linoleic acid and gamma-linolenic acid safe in epilepsy, with prolonged oral administration of linoleic acid and alpha-linolenic acid (in a 4:1 mixture) protecting rats from having seizures in four different epilepsy models, but the evening primrose oil-derived omega-6 fatty acid arachidonic acid inhibits sodium ion currents and synaptic transmission, while eicosanoid prostaglandin E(1) appears to have anticonvulsant activity. In light of these findings, it is suggested that formularies should now remove seizures or epilepsy as a side-effect of evening primrose oil, and should remove a history of seizures or epilepsy as a contraindication to taking evening primrose oil.

My thoughts on evening primrose oil
The whole topic of which oils and in which amounts are ideal for maintaining health and fighting disease is very complicated, but overall, in my opinion, I like to use fish oils or flax seed oil, and I'm still waiting for more research on evening primrose oil supplements before I form a strong opinion about them.

Research study
Evening primrose oil is derived from an American wildflower and is rich in essential fatty acids. Three clinical trials have looked at the botanical's effectiveness for children's atopic eczema, an allergic condition that causes patches of skin to become inflamed, dry and extremely itchy. Overall, the research suggests evening primrose oil may help with the condition.

Quantitative analysis of anti-inflammatory and radical scavenging triterpenoid esters in evening primrose oil.
J Agric Food Chem. 2004.
Cold pressed, nonraffinated evening primrose oil was recently found to contain lipophilic triterpenoidal esters with radical scavenging and anti-inflammatory properties. A simple and robust method for the quantitative analysis of these 3-O-trans-caffeoyl derivatives of betulinic, morolic, and oleanolic acid was developed and validated. Separation was achieved by normal phase chromatography on a Diol column and with hexane/ethyl acetate (50:50) as eluent. The analytes could be determined directly in the oil matrix, without need of a previous removal of the triglycerides. Normal phase LC ESI-MS with a makeup flow of polar modifier was used for checking the identity and purity of analyte peaks. Samples from 22 commercially available EPOs were analyzed. The average caffeoyl ester contents were 58 mg/100 g in cold pressed oils and 4.7 mg/100 g in partially raffinated oils. In fully raffinated evening primrose oil samples, the concentration was below the limit of detection. The influence of extraction temperature on the content of caffeoyl esters in nonraffinated evening primrose oil was investigated with seeds of Oenothera biennis and Oenothera lamarckiana, respectively. With O. lamarckiana, the concentration of caffeoyl esters in the oil increased with rising pressure and temperature, whereas no such dependency was found with O. biennis. Microscopic analysis revealed some differences in the histology of the seed testa, which may explain in part the differing behaviors in the extraction experiments. There was a difference between O. biennis and O. lamarckiana oils with respect to the relative amounts of the three esters. The temperature of the extraction process had no effect on the ratio of the compounds.

Emails
Q. I have heard all the so-called internal benefits of evening primrose. However, that is not what interests me. I am a certified aromatherapist, and have studied evening primrose infused oil as an anti wrinkle oil. However, I can find no information about this aspect---only the internal aspects. Can you give me any information about the anti-aging properties?
   A. We have not yet come across any research on this topic.

Q. Can an evening primrose oil supplement be taken the same day as turmeric or curcumin?
   A. They can probably be taken with most other supplements since they are quite safe.

Q. I was placed on IPO to help my breast. Not Lot pain there, but terrible fibromyalgia pain. In 6 years that I have dealt with it I have not had any relief. But I seem now to Have 50 to 75% relief. Only thing else placed on at that time was calcium with D. Any research on fibromyalgia pain relief with primrose.
   A. We haven't come across hardly any research with evening primrose oil and fibromyalgia.

Q. Do you know how evening primrose oil can be used in pregnancy or labor?
   A. I am not familiar with its use to induce labor or during pregnancy.

Q. I am wondering whether I am suitable to eat evening primrose oil as I am 18 years old. Also, is it better to eat it before you sleep or on an empty stomach. And how many pills to eat per day. Lastly, I'm wondering whether it is better to apply EPO cream on my face to reduce inflammation of eating the pill.
   A. Eating evening primrose oil with food in the morning is a good option. We are not familiar with using EPO cream.

Q. I'm a 21-year-old Asian girl and have been taking evening primrose oil since I first had my period (12 years old). It works well for the women in our family (including extended family members) for stomach cramp during menstruation. Maybe u can do some research in this area. My mum took evening primrose oil (500mg) almost everyday -- not anymore now cause she already menopause, but I'm lazy, so I only take a week before my period until the first 3 days of my period. So far, no side effects for us.

Q. I have been using Efamol oil of evening primrose for the past 40 years - about 3000 mg. per day. It cleared up my eczema, my calluses on my feet and i was able to give up wearing glasses. I take no prescription drugs and am decease free - unlike all my family members. I believe in it 100% and wish someone would do more research on it.

Can a person take evening primrose oil supplement and chasteberry supplement together?
   These natural supplements are not known to have any major side effects but we can't predict the effects on any one individual taking them either separately or together.

Is it ok to take more good Omega 6 in the form of GLA, which in my case is Evening Primrose Oil, than Omega 3? I take Omega 3 in the form of Krill Oil but I want to take a little more of the Evening Primrose Oil. The oil supplements help with my Eczema and dry skin. I use to take Fish oil but I had to take very high doses of it to see results and it gave me gas and made me burp horribly...so I tried the Krill Oil and it works a little better...the Evening Primrose Oils works for my Menstrual Cramps and my skin. I read some research on the net where a Dr. said that he believed that people should have an equal amount of Omega 6 or even a little more of Omega 6 than Omega 3 to prevent heart diseases...but I read so much that you should have more Omega 3 than Omega 6 and keep a healthy ratio between the two.....but Evening Primrose is a good Omega 6 that coverts to Prostaglandins in the body.....So can I consume just as much of Evening Primrose Oil (or any Omega 6 in the form of GLA) as Omega 3? Can I consume more of Evening Primrose Oil than Omega 3? Is it healthy to do so?
    There is no easy or simple answer since much depends on your individual body chemistry, genetics, and overall diet. You just have to try for yourself different amounts of each to see which works for you best.

is it true that you shouldn't take evening primrose oil if your on Birth Control Pills? Most women use Evening Primrose Oil to help them get pregnant.
    I see no obvious reason of an interaction between EVO pills and BCP.

I read a follow-up in the January 2010 issue of Prevention Magazine regarding the use of Evening Primrose oil supplement for thinning hair. I don't know when the original article appeared but this woman said she had great success with re-growth after using this supplement (no dosage mentioned). Do you know anything about this or any other natural way to try to re-grow hair loss from stress? I have been using 5% Rogaine for years, have had fair success, but would rather switch to a more natural product. I am a 63 year old female in relatively good health.
    I have not seen any research that indicates this dietary supplement is useful as a hair growth agent.

Advance Physician Formulas, Evening Primrose Oil, 1000 mg, 60 Softgels
Purchase Evening Primrose oil supplement 1000 mg
Buy Evening Primrose oil top quality or Diet Rx as an appetite suppressant

Usage, dosage: Take 1 - 2 evening primrose oil softgels daily with meals, or as directed by your qualified health consultant.

Evening Primrose oil 1000 consists of 100% pure, cold pressed oil of Evening Primrose (Oenothera lamarchiana), a potent source of Gamma Linolenic Acid (GLA), an omega 6 fatty acid produced in human metabolism.

Supplement Facts:
Amount Per Softgel
Calories - 10
Evening Primrose Oil 1000 mg
GLA (Gamma Linolenic Acid) - 90 mg

Fatty Acid profile of Evening Primrose Oil:
GLA - 18:3:6
Linoleic Acid 18:2:6
Oleic Acid 18:1:9
Misc. Fatty Acids - 8%