Pollen extract may be helpful in reducing menopausal symptoms, but studies in cancer patients are needed to confirm safety and effectiveness.
Pollen extract is an ingredient in a standard Swedish formula made from the pollen and pistils of grasses that are members of the Poaceae family. A few studies suggest that pollen extract may be helpful in relieving both premenstrual and menopausal symptoms. Although the mechanism by which this may occur is not well understood, pollen extract appears not to have hormonal effects. Therefore, it may be useful for breast cancer patients experiencing hot flashes. However, studies in cancer populations are needed to ensure safety, effectiveness, and to confirm that it does not negatively interact with chemotherapy drugs.
Purported Uses
To relieve symptoms of menopause
Some studies suggest that pollen extract may reduce symptoms such as hot flashes and improve quality of life in menopausal women, but studies that confirm safety and effectiveness in cancer patients are needed.
To relieve premenstrual symptoms
Some studies suggest that pollen extract may reduce premenstrual sleep disturbances.
Side Effects
Among the few studies conducted, there were no side effects that appeared to be related to pollen extract.
Special Point
Pollen extract should not be confused with propolis, which is pollen harvested by bees from many different plant families, and may also include other substances such as beeswax.
Brand Name
Relizen®, Femal®
Clinical Summary
Pollen extract is an ingredient in a standardized Swedish natural product that contains both pollen and pistils derived from members of the Poaceae family of grasses. It has been used as an herbal remedy to relieve premenstrual, perimenopausal, and menopausal symptoms such as fatigue, hot flashes, irritability, and sleeplessness. The exact mechanism of action remains unclear. However, in vitro and animal studies did not find estrogenic activity (1), suggesting it does not work through the modulation of hormones. This is of particular interest among patients with hormone-sensitive cancers who have limited options and may have safety concerns with more conventional methods to address such symptoms.
Initial open-label studies suggested that a standardized pollen extract was useful in alleviating premenstrual, perimenopausal, and menopausal symptoms (2)(3), although one of these studies combined the extract with royal jelly(3). In a follow-up randomized controlled trial (RCT), pollen extract was found to reduce hot flashes and improve quality of life in menopausal women (4). A double-blind RCT found a reduction in premenstrual sleep disturbances, which was more pronounced in women who identified irritability as their main symptom (5).
No studies have been conducted in cancer populations. Therefore, additional clinical trials are needed to confirm safety and efficacy of pollen extract, including for use among cancer patients.
Pollen extract should not be confused with propolis, which is pollen harvested by bees from many different plant families, and may also include other substances such as beeswax.
Purported Uses
Premenstrual symptoms
Menopausal symptoms
Mechanism of Action
There are two active ingredients in the formulation studied: a combined pollen and pistil extract (PI 82, 75%), which contains high levels of superoxide dismutase, and a pure pollen extract (GC FEM, 25%) (4). PI 82 pollen extracts are derived from Secale cereale (rye grass), Dactylis glomerata (orchard grass), and Pinus silvestris (Scots pine) while the pollen-pistil extract is derived from Zea mays. GC FEM pollen extract is derived from S. cereale, Z. mays, and P. silvestris (1). The preparation is standardized to contain 14 mg of amino acids per tablet (4).
Laboratory studies determined that the pollen extract preparation used in studies contained low concentrations of the phytoestrogens daidzin, daidzein, and genistin, that were considered to be subeffective. These studies also did not detect genistein, formononetin, or biochanin A (1). In vitro, purified Swedish pollen extract did not show inhibition of the cytochrome P450 2D6 enzyme (6). In addition, animal studies indicate that the pollen extract formulation at high doses did not cause uterine growth in immature female rats, suggesting no estrogenic effects (1).
The exact mechanism for reduction of menopausal symptoms remains unclear but one study suggests that the antioxidant properties of the ingredients may play a role (4).
Adverse Reactions
Among the few studies conducted, no related adverse events were reported (4)(5).
Herb-Drug Interactions
In an in vitro study, purified Swedish pollen extract did not inhibit the CYP2D6 enzyme (6).
Kimura H, Gruber P. Perimenopausal symptoms such as hot flushes and mood swings are reduced by a standardised pollen pistil extract. Climacteric. 2002;5(Suppl 1):85(abstr).
Winther K, Hedman C. A preparation containing pollen and pistil extracts combined with Royal Jelly reduces PMS and menopausal symptoms. Climacteric. 2002;5(Suppl 1):86(abstr).
