Evening primrose oil

Related Terms

(+)-catechin, aceite de onagra (Spanish), arachadonic acid (AA), cis-linoleic acid, dihomo-gamma-linolenic acid (DGLA), Echte Nachtkerze (German), ellagic acid, EPO, fever plant, gallic acid, gamma-linolenic acid (GLA), gamolenic acid (GLA), herbe aux anes (French), Huile D'Onagre (French), kaempe natlys, King's Cureall, la belle de nuit (French), linoleic acid (LA), nachtkerzenol (German), night willow-herb, Oenothera biennis L., Oenothera communis Leveill, Oenothera graveolens Gilib, Oenothera paradoxa, omega-6 essential fatty acid, Onagra biennis Scop, Onagraceae (family), Onogra vulgaris, onagre bisannuelle, pentagalloylglucose, penta-O-galloyl-beta-D-glucose, primrose oil, procyanidins, scabish, Spach, stella di sera, sun drop, Teunisbloem (Dutch), unsaturated fatty acids.
According to secondary sources, Epogam (40mg GLA and 10mg vitamin E) and Efamast (gamolenic acid) had their product licenses withdrawn October 7, 2002, following a review by the MCA/Committee on Safety of Medicines (CSM) of all the relevant information. It was determined that the information available did not support the standard of efficacy required for the authorization of these products as medicines for the treatment of eczema and mastalgia.
Combination product examples: Bronchicum? Tropfen (thyme and primrose), Bronchipret? TP FCT (thyme and primrose), Bronchicum? Elixir S (thyme and primrose).
Zestra? (borage seed oil, evening primrose oil, angelica root extract, and coleus extract)
The combination compound was called IOVE and was composed of 60mg isoflavones, 440mg primrose oil (consisting of 9-10% gamma linolenic acid (GLA)), and 10mg vitamin E.

Background

Native Americans traditionally considered the evening primrose plant's seeds, leaves, and roots to be a food. They also used the plant to treat bruises or wounds, hemorrhoids, stomach problems, and sore throats.
Oil extracted from evening primrose (Oenothera biennis) plant seeds consists of a high amount of unsaturated fatty acids. These fatty acids include omega-6 fatty acids, linolenic acid, and gamma-linolenic acid (GLA). GLA has been licensed for treating breast pain and eczema in numerous countries.
Evening primrose oil (EPO) has been studied for several disorders, particularly those affected by metabolic products of essential fatty acids. There is good scientific evidence to support EPO for eczema treatment.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *


Overall, evidence suggests a moderate improvement of eczema with EPO. Large, well-designed studies are needed to provide a definitive conclusion. EPO has been approved for atopic dermatitis and eczema in several countries outside the United States.

 B


Overall, evidence suggests a moderate improvement of eczema with EPO. Large, well-designed studies are needed to provide a definitive conclusion. EPO has been approved for atopic dermatitis and eczema in several countries outside the United States.

 B


Early research suggests a beneficial effect of evening primrose oil (EPO) over corn oil in breast tumors. In human research, EPO treatment helped prevent breast cancer recurrence. However, additional studies using EPO alone are needed in this area.

 C


Early research suggests a beneficial effect of evening primrose oil (EPO) over corn oil in breast tumors. In human research, EPO treatment helped prevent breast cancer recurrence. However, additional studies using EPO alone are needed in this area.

 C


Human research is lacking for beneficial effects in EPO use for breast cysts. More well-designed studies are needed before a conclusion may be made.

 C


Human research is lacking for beneficial effects in EPO use for breast cysts. More well-designed studies are needed before a conclusion may be made.

 C


Evening primrose oil (EPO) is licensed for the treatment of mastalgia (breast pain) in the United Kingdom. Conflicting evidence has been reported with EPO in the treatment of breast pain. Additional well-designed studies are needed before a firm conclusion may be made.

 C


Evening primrose oil (EPO) is licensed for the treatment of mastalgia (breast pain) in the United Kingdom. Conflicting evidence has been reported with EPO in the treatment of breast pain. Additional well-designed studies are needed before a firm conclusion may be made.

 C


It is unclear if evening primrose oil (EPO) is an effective treatment for bronchitis. Several studies have evaluated EPO in combination with thyme with some evidence of benefit. Additional well-designed studies using EPO alone are needed.

 C


It is unclear if evening primrose oil (EPO) is an effective treatment for bronchitis. Several studies have evaluated EPO in combination with thyme with some evidence of benefit. Additional well-designed studies using EPO alone are needed.

 C


Research with EPO has shown a lack of significant beneficial effects on heart function and health. Early research suggests that EPO may decrease blood pressure. Additional research is needed in this area.


 C


Research with EPO has shown a lack of significant beneficial effects on heart function and health. Early research suggests that EPO may decrease blood pressure. Additional research is needed in this area.


 C


Historically, EPO has been used to promote easier birth, prevent preterm delivery, induce labor, and ripen the cervix. Low quality studies have revealed that evidence of benefit is lacking. Additional well-designed studies are needed on this topic.

 C


Historically, EPO has been used to promote easier birth, prevent preterm delivery, induce labor, and ripen the cervix. Low quality studies have revealed that evidence of benefit is lacking. Additional well-designed studies are needed on this topic.

 C


EPO studies have demonstrated beneficial effects on serum markers in diabetes. Additional studies are required before a conclusion may be made.

 C


EPO studies have demonstrated beneficial effects on serum markers in diabetes. Additional studies are required before a conclusion may be made.

 C


Gamma-linolenic acid (GLA), one of the components of evening primrose oil, may be helpful in people with diabetic neuropathy. Additional studies are needed in this area.

 C


Gamma-linolenic acid (GLA), one of the components of evening primrose oil, may be helpful in people with diabetic neuropathy. Additional studies are needed in this area.

 C


Individuals with dry eyes had improved symptoms after supplementation with GLA, a component of EPO. Additional research is needed in this area.

C


Individuals with dry eyes had improved symptoms after supplementation with GLA, a component of EPO. Additional research is needed in this area.

C


EPO may benefit people with dyslexia by improving movement skills. However, many studies conducted were low quality or EPO was part of a combination product. Further high quality research evaluating EPO alone is needed.

 C


EPO may benefit people with dyslexia by improving movement skills. However, many studies conducted were low quality or EPO was part of a combination product. Further high quality research evaluating EPO alone is needed.

 C


Human research has shown EPO may lower cholesterol and triglycerides. However, there are conflicting reports. Additional studied are needed before a conclusion may be made.

 C


Human research has shown EPO may lower cholesterol and triglycerides. However, there are conflicting reports. Additional studied are needed before a conclusion may be made.

 C


Evening primrose oil has been studied in people with ulcerative colitis with evidence of benefit. The effects of EPO alone are unclear. Additional research is warranted in this area.

 C


Evening primrose oil has been studied in people with ulcerative colitis with evidence of benefit. The effects of EPO alone are unclear. Additional research is warranted in this area.

 C


Clinical trials have been conducted to assess the effects of EPO on liver cancer with mixed results. Additional studies are required before a conclusion may be made.

 C


Clinical trials have been conducted to assess the effects of EPO on liver cancer with mixed results. Additional studies are required before a conclusion may be made.

 C


Some research has shown that evening primrose lacks benefit in liver disease symptoms. Other studies suggest that EPO may reduce itching in people with liver disease. Additional, well-designed studies are necessary before a conclusion may be made.

 C


Some research has shown that evening primrose lacks benefit in liver disease symptoms. Other studies suggest that EPO may reduce itching in people with liver disease. Additional, well-designed studies are necessary before a conclusion may be made.

 C


Investigation of linoleic acid (LA) and gamma-linolenic acid (GLA) in the management of MS began in the 1970s. However, evidence is limited regarding EPO for multiple sclerosis. Additional research is needed in this area.

 C


Investigation of linoleic acid (LA) and gamma-linolenic acid (GLA) in the management of MS began in the 1970s. However, evidence is limited regarding EPO for multiple sclerosis. Additional research is needed in this area.

 C


Research suggests a lack of evidence for EPO's efficacy in weight-loss and obesity. Additional studies are needed before a conclusion may be made.

 C


Research suggests a lack of evidence for EPO's efficacy in weight-loss and obesity. Additional studies are needed before a conclusion may be made.

 C


Although primrose oil has been suggested as a possible treatment for bone loss and osteoporosis, there is a lack of research involving primrose oil alone. Well-designed research is needed before a firm conclusion may be made.

C


Although primrose oil has been suggested as a possible treatment for bone loss and osteoporosis, there is a lack of research involving primrose oil alone. Well-designed research is needed before a firm conclusion may be made.

C


Studies with high doses of evening primrose oil shoed evidence of benefit in people with chronic fatigue syndrome. However, additional well-designed studies are needed before a conclusion may be made.

 C


Studies with high doses of evening primrose oil shoed evidence of benefit in people with chronic fatigue syndrome. However, additional well-designed studies are needed before a conclusion may be made.

 C


Evening primrose oil may have effects on chemicals in the blood called prostaglandins, which may play a role in pre-eclampsia. The combination of EPO and fish oil may be equally as effective as magnesium oxide for pre-eclampsia. Further research in this area is needed.

 C


Evening primrose oil may have effects on chemicals in the blood called prostaglandins, which may play a role in pre-eclampsia. The combination of EPO and fish oil may be equally as effective as magnesium oxide for pre-eclampsia. Further research in this area is needed.

 C


There have been reports of EPO improving symptoms of Raynaud's phenomenon. Well-designed human studies are needed before a conclusion can be made.

 C


There have been reports of EPO improving symptoms of Raynaud's phenomenon. Well-designed human studies are needed before a conclusion can be made.

 C


Evening primrose oil for arthritis treatment has conflicting results. GLA may benefit arthritis better than corn oil. More research is needed before a firm conclusion can be made.

 C


Evening primrose oil for arthritis treatment has conflicting results. GLA may benefit arthritis better than corn oil. More research is needed before a firm conclusion can be made.

 C


An herbal combination product containing primrose has been used in people with sinus inflammation. Additional high quality research in this area is needed.

 C


An herbal combination product containing primrose has been used in people with sinus inflammation. Additional high quality research in this area is needed.

 C


Early research with evening primrose oil reports a lack of benefit for treating scale-like dry skin. However, additional studies are needed to confirm this conclusion.

 C


Early research with evening primrose oil reports a lack of benefit for treating scale-like dry skin. However, additional studies are needed to confirm this conclusion.

 C


A combination product containing EPO has had conflicting results for cellulite reduction. Well-designed studies on EPO alone are needed before conclusions can be drawn.

 C


A combination product containing EPO has had conflicting results for cellulite reduction. Well-designed studies on EPO alone are needed before conclusions can be drawn.

 C


Studies have described the effects of individuals receiving EPO after consuming alcohol and in people with alcoholism. However, well-designed studies evaluating EPO alone are lacking. Additional research is warranted before a conclusion may be made.

 D


Studies have described the effects of individuals receiving EPO after consuming alcohol and in people with alcoholism. However, well-designed studies evaluating EPO alone are lacking. Additional research is warranted before a conclusion may be made.

 D


Research has demonstrated a lack of efficacy for evening primrose oil (EPO) in people with asthma. Further research is needed to confirm this conclusion.

 D


Research has demonstrated a lack of efficacy for evening primrose oil (EPO) in people with asthma. Further research is needed to confirm this conclusion.

 D


Several studies show a lack of benefit from evening primrose oil in treating ADHD. Further research is needed to confirm this conclusion.

 D


Several studies show a lack of benefit from evening primrose oil in treating ADHD. Further research is needed to confirm this conclusion.

 D


In human research, evidence of benefit following GLA (a component of EPO) supplementation was lacking in individuals with hepatitis B. Additional study is needed in this area.

 D


In human research, evidence of benefit following GLA (a component of EPO) supplementation was lacking in individuals with hepatitis B. Additional study is needed in this area.

 D


In infants, various effects on fatty acid levels have been described with EPO and fish oil. However, well designed research evaluating EPO alone is still warranted.

 D


In infants, various effects on fatty acid levels have been described with EPO and fish oil. However, well designed research evaluating EPO alone is still warranted.

 D


Some research reports a lack of evidence that EPO is useful for menopause symptoms, such as flushing and bone mineral density. A combination EPO essential oil and massage may reduce blood pressure. Additional study is needed in this area.

 D


Some research reports a lack of evidence that EPO is useful for menopause symptoms, such as flushing and bone mineral density. A combination EPO essential oil and massage may reduce blood pressure. Additional study is needed in this area.

 D


EPO is widely used internationally by women for symptoms of premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD). According to some experts, EPO is regarded as an effective treatment for PMS symptoms. However, evidence is conflicting with studies showing a lack of benefit. Additional research is needed in this area.

 D


EPO is widely used internationally by women for symptoms of premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD). According to some experts, EPO is regarded as an effective treatment for PMS symptoms. However, evidence is conflicting with studies showing a lack of benefit. Additional research is needed in this area.

 D


Initial research lacks a benefit from EPO for psoriasis treatment. Some studies have been done in combination with fish oil, and the effects of EPO alone are unclear. More well-designed trials are needed before a conclusion can be drawn.

D


Initial research lacks a benefit from EPO for psoriasis treatment. Some studies have been done in combination with fish oil, and the effects of EPO alone are unclear. More well-designed trials are needed before a conclusion can be drawn.

D


Results from most studies do not support EPO use for schizophrenia. Additional well-designed clinical trials are needed.

 D


Results from most studies do not support EPO use for schizophrenia. Additional well-designed clinical trials are needed.

 D
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

Dosing

Adults (18 years and older)
For alcohol intoxication, six 500 milligram capsules of EPO have been taken by mouth daily for one week.
For bronchitis, one tablet of a thyme-primrose combination product (Bronchipret? TP FCT) has been taken by mouth three times daily for 11 days. Two other combination products, Bronchicum? Elixir S and Bronchcium? Tropfen, have been taken by mouth in doses of 6 x 5 milliliters of fluid or 5 x 1 milliliter of drops for 7-9 days.
For breast pain (mastalgia), 1-3 grams or 2.4 milliliters of EPO, 1-6 capsules of EPO, or 240-320 milligrams of GLA (Efamast?, Efamol?) has been taken by mouth 1-3 times daily for up to six months.
For heart health, 10-30 milliliters of EPO (Efamol?) has been taken by mouth daily for four months. Additionally, 3 grams of a linoleic-GLA combination has been taken by mouth for two months.
For childbirth (labor induction or cervical ripening), one EPO capsule has been taken by mouth three times daily for one week.
For diabetes, two Efamol? capsules, containing 45 milligrams GLA and 360 milligrams LA (linoleic acid), have been taken by mouth daily for four months and then increased to four Efamol? capsules daily for an additional eight months.
For diabetic neuropathy (nerve damage), 360-480 milligrams of GLA have been taken by mouth daily for up to 12 months.
For dry eyes, six EPO capsules (QarmaT, EquazenT) have been taken by mouth daily for six months.
For eczema (atopic dermatitis), 1-4 EPO capsules (360 milligrams linoleic acid and 40-45 milligrams GLA per capsule) have been taken by mouth twice daily for up to 12 weeks. Additionally, 4-12 capsules (500 milligrams EPO per capsule) have been taken by mouth daily in two divided doses for up to five months (Efamol?). EPO doses have ranged from 0.5 grams-0.5 grams/kilogram taken by mouth for 3-16 weeks. A dose of 1 milliliter of 20% EPO has been applied to the skin twice daily for up to four months. EPO has been applied to the arms for two weeks.
For high cholesterol, four capsules, containing 0.3 grams EPO, have been taken by mouth three times daily for 16 weeks. Additionally, 1.5-2 grams of EPO has been taken by mouth twice daily for 1-3 months.
For liver cancer, 36 capsules, containing 500 milligrams EPO per capsule (Efamol?) daily (totaling 1.44 grams GLA daily) have been taken by mouth.
For liver disease, 2 grams of Efamol? has been taken by mouth twice daily for 12 weeks.
For lupus, 5 grams of EPO has been taken by mouth daily.
For premenstrual syndrome (PMS), 500-6,000 milligrams of EPO or 6-12 capsules EPO have been taken by mouth 1-4 times daily for up to 10 months (Efamol?).
For rheumatoid arthritis, 540-6,000 milligrams of EPO and 20-30 milliliters of EPO have been taken by mouth daily for 3-12 months.
For schizophrenia, 6-8 grams of EPO has been taken daily in divided doses. Eight Efamol? capsules have been taken by mouth daily for two to four months.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Interactions

Interactions with Drugs
Evening primrose oil may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. People taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Evening primrose oil may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin?) or heparin, anti-platelet drugs such as clopidogrel (Plavix?), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin?, Advil?) or naproxen (Naprosyn?, Aleve?).
Evening primrose oil may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be increased in the blood, and may cause increased effects or potentially serious adverse reactions. People using any medications should check the package insert, and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.
Evening primrose oil may increase the amount of drowsiness caused by some drugs. Examples include benzodiazepines such as lorazepam (Ativan?) or diazepam (Valium?), barbiturates such as phenobarbital, narcotics such as codeine, some antidepressants, and alcohol. Caution is advised while driving or operating machinery.
Evening primrose oil may cause low blood pressure. Caution is advised in people taking drugs that lower blood pressure.
Evening primrose oil may also interact with agents for arthritis, cancer, or obesity; agents for the brain, skin, stomach, or intestines; agents that lower cholesterol; alcohol; aldose reductase inhibitors; anesthetics; antibiotics; anticonvulsants; antidepressant agents such as monoamine oxidase inhibitors (MAOIs) or selective serotonin reuptake inhibitors (SSRIs); anti-inflammatory agents; antipsychotics; antiviral agents; beta-blockers; celecoxib; CNS depressants or stimulants; corticosteroids; COX-2 inhibitors; Faslodex?; phenothiazines; seizure threshold-lowering agents; tamoxifen; or vincristine.

Attribution

This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

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