Herbal supplements interactions with oral oestrogen-based contraceptive metabolism and transport

The increased use of herbal supplements as complementary or alternative medicines has become a clinical conundrum due to the potential for herb-drug interactions. This is exacerbated by an increased supply of new herbal supplements in the market claiming various health advantages. These herbal supplements are available as over-the-counter self-medications. Herbal supplements are generally perceived as efficacious without side effects commonly associated with conventional drugs. However, despite regulations, claims related to their therapeutic effects are mostly unsupported by scientific evidence. These products often lack suitable product quality controls, labelled inadequately and with batch to batch variations, potentially compromising the safety of the consumer. Amongst health practitioners, the greatest concern is related to the lack of chemical characterization of the active compounds of the herbal supplements. The interaction between these different active components and their concomitant effects on other conventional drugs is generally not known. This review will focus on herbal supplements with the potential to effect pharmacokinetic and pharmacodynamic properties of oestrogen-based oral contraceptives. The use of herbal supplements for weight management, depression, and immune boosting benefits were selected as likely herbal supplements to be used concomitantly by women on oral contraceptives.