In addition to hair growth treatments made with minoxidil, the FDA-approved hair growth ingredient, and rosemary oil, Aral also suggests products infused with coffeeberry extract to promote healthy hair growth. verifyErrors }}{{ message }}{{ /verifyErrors }}{{ Most topicals that are formulated with active ingredients are made to leave on the scalp for optimum efficacy," Hill says. She suggests seeking out a formula that's "light enough to penetrate the scalp without leaving a residue on the hair fiber and that's formulated to increase cellular turnover, reduce inflammation, respect the natural balance of the scalp’s microbiome and can be shampooed out." She recommends products that contain: Good Housekeeping Institute Beauty Lab executive director Birnur Aral, Ph.D., has led clinical and consumer testing in the Beauty Lab for over 15 years. She has R&D experience through her seven-year stint at Unilever U.S. and contributes her expertise across beauty categories, including haircare products. For this piece, she worked with beauty writer Katie Berohn to curate the best hair growth oils based on her haircare ingredient evaluations. It's important to understand the difference between the ingredients in hair growth oils. "The only FDA-approved over-the-counter topical ingredient for the treatment of hair loss is Minoxidil," says Danusia Wnek, senior chemist at the Good Housekeeping Institute Beauty, Health & Sustainability Lab. It is known to slow down hair loss and stimulate hair growth but "the mechanism of action on the hair follicle is very limited," according to this scientific review. "Unless it contains minoxidil, a hair growth oil won’t increase hair growth (the number of strands on your scalp); instead it will lubricate hair, preventing breakage and damage," she adds. Below, find the best hair growth oils you can use at home for healthier, longer strands.