Grapefruit seed extract

Grapefruit seed extract (GSE), also known as citrus seed extract, is a liquid

Despite claims that GSE has antimicrobial effects,^[10] there is no scientific evidence that GSE has such properties.^[11][8] Some evidence indicates that the suspected antimicrobial activity of GSE was due to the contamination or adulteration of commercial GSE preparations with synthetic antimicrobials or preservatives.^[1][2][12] These chemicals were not present in grapefruit seed extracts prepared in the laboratory, and GSE preparations without the contaminants were found to possess no detectable antimicrobial effect.^[1] Although citrus seed extract is sold in health food markets,^[12] there is no good evidence for any antimicrobial activity.^[1]

Phytochemicals

Analysis shows the

GSE is prepared by grinding the grapefruit seed and juiceless pulp, then mixing with glycerin.[1] Commercially available GSE is made from the seed, pulp, glycerin, and synthetic preservatives all blended together.^[1]

Health claims and safety concerns

Although various health claims for using GSE are marketed in the dietary supplement industry, there is no scientific evidence from high-quality clinical research that it has any health effects, as of 2018.^[8][11] Phytochemicals in grapefruit seeds, particularly furanocoumarins and flavonoids, may cause adverse effects on health resulting from grapefruit–drug interactions that influence the intended therapeutic effects of some 85 prescription drugs.^[11][18] The main safety concern about GSE is inhibition of the liver enzyme, cytochrome P450, which controls liver metabolism of drugs; consequently, its inhibition by GSE unpredictably increases the blood concentrations of prescribed drugs.^[18]

References