Evening Primrose oil capsule
Introduction: Evening primrose is a plant with the scientific name “Oenothera biennis” that grows in North America and has been brought from there to Europe and parts of Asia and has been grown there. Pharmaceutical part of this plant include the oil that is extracted and collected from Fresh and ripe grains of plants in the flowering season. Medicinal properties of this oil has long been known and used orally and topically.
Pharmacology and mechanism of action:  
Evening primrose oil is belonging omega-6 acids and are commonly "contains linoleic acid (80-65%), gamma-linolenic acid (14-8%), oleic acid (11.6%) and palmitic acid (10.7%).  Gamma - linolenic acid (GLA) in the body is converted to Dihimo-GLA and then is change to prostaglandin E1 (PGE1) with delta-6-desaturase enzyme. PGE1 has anti-inflammatory and cell membrane stabilizer effects in body. GLA is found in the composition of breast milk and has a role in growth and development of the infant’s nervous system. laboratory studies show that, evening primrose oil has antioxidant effects  and Several studies also has established the beneficial effects of this product in inflammatory diseases, nerve disorders caused by diabetes, high blood cholesterol, high blood pressure and irritable bowel syndrome (IBS) and control symptoms of premenstrual syndrome undesirable (PMS). 
Drug and Dosage:
Rheumatoid arthritis: Use of 6 capsules of evening primrose oil daily may reduce the symptoms of rheumatoid arthritis and in result reduce the use of NSAIDs .
Diabetic neuropathy: According to studies, it has been established that a daily intake of 6 capsules of evening primrose oil by patients with diabetes and neurological disorders,  considerably resulting in improved neurological symptoms such as increased speed signals motor nerves, improves sensory nerve function, muscle activity combined, increased tendon reflexes and sensory functions in the hands and legs of patients.
High blood cholesterol: Studies have shown that taking 2-3 capsules of evening primrose oil per day for 4 months, can lead to a reduction in triglycerides, total cholesterol and increases LDL blood levels of HDL (beneficial form of fat in the blood).

Irritable Bowel Syndrome (IBS): Intake of 4 capsules 1g of evening primrose oil per day, may improve symptoms of irritable bowel syndrome such as abdominal pain, bloating, diarrhea, constipation and nausea in patients. Studies have shown that most symptoms are dramatically reduced during the third month, of this product consumption. 
Periodic chest pain (Mastalgia): Several studies indicate that daily usage of evening primrose oil has positive effects on relieving the chest pain during menstruation of women. According to the survey, for control the chest pain during menstruation, it is administrated 1-2 capsules of evening primrose oil 1000 mg twice a day for a month and In the event of symptoms recovery of, usage of this drug continues for 1-2 other months.
Cancer: Laboratory studies have shown that evening primrose oil is a considerable antioxidant effect. The beneficial effects of antioxidants has been completely proven in removing of free radicals in the body and preventing the cancer. also clinical studies in patients with breast cancer have shown that the  GLA in evening primrose oil can be have considerably beneficial effects in improving the patients receiving tamoxifen compared with patients who receive only tamoxifen.
Premenstrual syndrome (PMS): Numerous studies have demonstrated the positive effect of evening primrose oil in controlling the physical and physiological symptoms of premenstrual syndrome in women. Premenstrual syndrome (PMS) is symptoms of physical and mental relatively "severe” that occurs before menstruation due to changes in estrogen and progesterone hormone levels during the menstrual cycle. common symptoms of PMS, including bloating, breast tenderness, weight gain, aggression, poor concentration, headaches, backaches, eating, crying, irritability, anxiety, mood swings and depression that over 85% of women experience some of these symptoms before menstruation. Studies have shown that daily usage of 2 capsules of evening primrose oil at the start of the luteal phase and increase it to 4 per day can improve the symptoms of this syndrome. In order to make a full recovery in some women it is required to taking these products up to 3 months.
Eczema: reviews of 9 clinical studies demonstrates the efficacy and atopic eczema is a skin condition achieve remission in symptoms.
Before using this drug, consult with your doctor or pharmacist in the following cases :
In case of hypersensitivity to evening primrose oil or other vegetable oils, gelatin, protective materials, colors and any food or drug.
In the case of co-current use with other medicinal products specially with  'anti-epileptic and anti-clotting drugs.
In the case of epilepsy or blood coagulation disorders
Note the followings during the course of treatment with these products:
Meal this drug at interval regulations and complete the treatment course
Do not use the drug over the dose and time that has been recommended by your physician or pharmacist.
You can take capsules of evening primrose oil with some water before or along a meal.
If you forget a dose of medicine, take it as soon as you remember, but if almost "the time has come to take the next turn, take the prescribed dose and do not double the intake.
Use in lactation and pregnancy
Gamma-linolenic acid (GLA) found in evening primrose oil is a natural component of breast milk, and it seems that it will be useful for the development of breast-fed infant’s nervous system. Also, due to the beneficial effects of evening primrose oil in healing atopic eczema, It was suggested that consumption of evening primrose oil in nursing mothers, regulate the amount of fat in breast milk and thereby improve the infant eczema therapy.
A few studies have shown that taking evening primrose oil during pregnancy can prevent preeclampsia (Pre-eclampsia). This products can help to facilitating delivery and preventing delivery delays. It is recommended that pregnant women use this drug from 34 weeks of pregnancy 1000-500 mg daily and increase it to 2000 mg per day from the week 38 onward. For using any of drugs or dietary supplements such as evening primrose oil during pregnancy should consult with your doctor.

Side effects and precautions
Possible side effects of these products for use in oral form are uncommon but can occur in some people and can include mild gastrointestinal symptoms such as nausea, vomiting, diarrhea and bloating.
Due to the possibility of lowering the threshold of seizures in patients with schizophrenia, that use phenothiazine and anti-seizure and epilepsy medications, use of evening primrose oil consumption is not recommended in these patients.
Evening primrose oil has preventing effect on flocculation in blood vessels so should not be combined with other anti-clotting drugs or consumed in patients with blood coagulation disorders. 
keep drug below 25ﹾC
keep drug away from light and moisture and keep in original pack.
keep it away from children reach
Do not use expired drug.
Dosage forms
Soft capsules of evening primrose 1 g is released in 50 numerical boxes.