Evening primrose oil's roots go far and deep, literally. In addition to eating its boiled roots, Native Americans traditionally soaked evening primrose plants in warm water to make a poultice for healing wounds, bruises, and hemorrhoids. Thousands of years later, I've been coming across evening primrose oil in skin care products such as gloTherapeutics gloConditioning Restorative Mask, Dermaxime Rejuvenating Night Cream, and Jurlique Herbal Recovery Eye Gel. Might these iterations of an ancient herb deliver equal, or even better, benefits?
Evening primrose (oenothera biennis) is a hardy plant most often found in dry, sunny meadows. Its pale yellow, phosphorescent blossoms grow in clusters along the flower stalk, opening at dusk to attract pollinating insects. The entire plant is edible, and the roots have a flavor similar to parsnips. The seeds of evening primrose, which grow within an oblong, hairy capsule, have numerous medicinal properties.
Firstly, they are rich in (omega-6) fatty acids, including linoleic acid (LA) gamma linoleic acid (GLA). The human body uses LA to produce GLA, which helps maintain stratum corneum cohesion and reduce transepidermal water loss. Other sources of GLA include hemp, borrage, spirulina (an algae), and black currant oils. Because of its GLA content, evening primrose oil is often used to treat PMS and menopausal symptoms, which worsen when the body is deficient in essential fatty acids. In Germany, evening primrose oil is approved for these uses, as well as for lowering cholesterol and reducing juvenile hyperactivity.
As an oral supplement, evening primrose oil has shown promise in treating nerve disorders, such as multiple sclerosis and rheumatoid arthritis, and in promoting weight loss. Taking evening primrose oil orally can also confer physical benefits, including relief from dry eyes, brittle nails, sunburn, and acne (especially when combined with zinc). Clinical studies with guinea pigs in the 1980's proved that the consumption of evening primrose oil can reverse symptoms of essential fatty acid deficiency, which is associated with various human health disorders.
In terms of topical application, evening primrose oil is no less beneficial. Several human trials have demonstrated its efficacy in treating inflammation, eczema, pruritus, xerosis, and scaliness. More than 20 randomized, controlled studies have evaluated the effects of gamma linoleic acid on skin, and the majority of data suggests that GLA application enhances the epidermal barrier. Because of its ability to dilute sebum production, evening primrose oil is good at calming acne flare-ups, while at the same time hydrating skin. The astringent properties of the plant's juice can soothe skin irritations and inflammations.
Evening primrose's high level of antioxidants, which counteract the detrimental effects of oxidation in living tissue, make it a worthy inclusion in skin preparations for smoothing roughness, reducing fine lines, and lightening dark circles around the eyes. A group of Canadian researchers recently identified the specific antioxidant compounds present in evening primrose oil. One of these is catechin, a flavonoid that has the potential to inhibit the growth of cancerous tumors and lower the risk of heart disease.
Evening primrose oil is sold commercially as an oil or in capsules (usually 500 mg), both of which should be standardized to contain 8% gamma-linolenic acid. Because this oil tends to go rancid rather quickly (due to its high levels of unsaturated fat), the capsule form may be more practical for regular use. The recommended oral dosage is 2-8 grams daily, though a medical professional should be consulted for serious health problems. A DIY ointment for treating skin inflammations can be prepared by mixing one part diced plant with four parts heated petroleum jelly or glycerin. The mixture should be stored in a tightly sealed container and refrigerated.
Even though the therapeutic use of herbs is a time-honored and generally safe approach to strengthening the body and improving overall health, certain components within evening primrose oil can interact with other medications (in particular phenothizines, nonsteroidal anti-inflammatory drugs, and blood-thinning drugs) and trigger negative side effects. Typically rare and indicative of overdose, adverse reactions include headache, nausea, loose stools, and skin rash. In general, evening primrose oil is considered safe enough even for children and breastfeeding mothers, since breast milk is a natural source of both LA and GLA.
Despite the many clinical trials that have arisen from anecdotal evidence of evening primrose oil's powers, human studies have not always met with success. Some suggest that it can take about three months of evening primrose oil consumption before a positive response is observed. Commercial samples of evening primrose oil typically contain only trace amounts of its beneficial substances (see: angel dusting). Ultimately, cosmeceutical formulations, which need not meet rigid standards of safety and efficacy, won't suffice as therapy for most medical conditions. But research on evening primrose oil looks promising, and it certainly wouldn't be the first time a native tribe beat the modern medical community to the punch.