An extract created from the seed of the grapefruit plan. It is also known simply as GSE.

Marketed as an antimicrobial (a substance that destroys harmful microorganisms), grapefruit seed extract may kill some bacteria by affecting acidity. Scientific research does not fully validate this claim; some studies have found that GSE does not significantly affect the growth of harmful bacteria. However, there is ample evidence demonstrating the antioxidant properties of the extract.

In lubricants and other sexual health products, grapefruit seed extract is used to prevent yeast infections and other microorganism over growths.