Evening Primrose Oil (EPO) is a dietary supplement derived from the seeds of the *Oenothera biennis* plant. It is a rich source of gamma-linolenic acid (GLA), an omega-6 essential fatty acid. GLA is a precursor for prostaglandin E1 (PGE1), a compound with anti-inflammatory and vasodilatory properties. In the Indian context, it is widely used as a nutraceutical for managing symptoms of hormonal imbalances, dermatological conditions, and chronic inflammatory states, though robust clinical evidence for many uses is variable.
Adult: 1000mg to 3000mg per day, in divided doses (e.g., 1000mg twice or thrice daily). For mastalgia/PMS: 2000-3000mg/day from day 15 of cycle to menses onset. For eczema: 2000-4000mg/day.
Note: Take with meals, preferably containing some fat, to enhance absorption. Swallow softgel capsules whole with a full glass of water. Do not crush or chew. For best results, use consistently for at least 8-12 weeks to assess efficacy.
The primary active component, Gamma-Linolenic Acid (GLA, C18:3 n-6), corrects a relative deficiency in the delta-6-desaturase enzyme pathway. This enzyme converts dietary linoleic acid to GLA. By providing pre-formed GLA, EPO bypasses this rate-limiting step, ensuring adequate production of Dihomo-γ-linolenic Acid (DGLA). DGLA is incorporated into cell membranes and serves as a substrate for the synthesis of Prostaglandin E1 (PGE1), which has potent anti-inflammatory, vasodilatory, and anti-proliferative effects. It also competitively inhibits the conversion of arachidonic acid to pro-inflammatory series-2 prostaglandins and leukotrienes.
Pregnancy: Category N (Not classified by US FDA). Generally avoided in early pregnancy due to theoretical uterine stimulant effect. Some studies use it in late pregnancy for cervical ripening. Use only if potential benefit justifies potential risk and under strict obstetric supervision.
Driving: Unlikely to affect ability. Dizziness has been rarely reported.
| Phenothiazines (e.g., Chlorpromazine) | May lower seizure threshold; increased risk of seizures. | Major |
| Anticoagulants/Antiplatelets (Warfarin, Aspirin, Clopidogrel) | Theoretical increased risk of bleeding due to antiplatelet effect of PGE1. Monitor INR closely. | Moderate |
| Cyclosporine | EPO may enhance immunosuppressive effect, risk of toxicity. Monitor cyclosporine levels. | Moderate |
| Chemotherapy (especially for breast cancer like Tamoxifen) | Theoretical interaction due to fatty acid metabolism. Avoid concurrent use unless under oncologist's advice. | Moderate |
| Anesthetics | Potential for increased seizure risk. Discontinue prior to surgery. | Moderate |