When shopping for a hair-loss shampoo that supports healthy hair growth, experts recommend looking for formulas that focus on scalp health, help reduce hair fall, and strengthen hair strands. Gaunitz advises choosing shampoos with natural active ingredients that minimize inflammation and prevent microbial overgrowth. “Ingredients such as tea tree oil, rosemary oil, green tea extract, saw palmetto, aloe, and arnica are all fantastic ingredients to look for,” he says. He also notes that the first five ingredients typically make up 97% of the formula, so seek shampoos that avoid harsh surfactants and parabens, and instead lean into nourishing actives for cleaner, fuller hair.

Rosemary Oil: Rambhia highlights a 2015 study comparing rosemary oil to 2% minoxidil for treating androgenetic alopecia. It found that rosemary oil was just as effective in increasing hair count after six months. “The oil works by improving circulation to hair follicles and has anti-inflammatory properties that may help create a healthier scalp environment for hair growth,” she says.

Tea Tree Oil: “This ingredient has antimicrobial properties that can help maintain scalp health and may reduce inflammation that could inhibit hair growth,” says Rambhia. A shampoo with tea tree oil is a great option if you’re prone to buildup, dryness, or flaking. “A clean, healthy scalp provides the optimal environment for hair follicles to function properly,” she adds.

Green Tea Extract: Known for its potent antioxidants, green tea extract may help block DHT (dihydrotestosterone), a hormone linked to hair loss. “By potentially reducing DHT activity, green tea extract could help preserve existing hair follicles,” says Rambhia.

Saw Palmetto: Rambhia explains that this botanical may help block 5-alpha reductase, the enzyme that converts testosterone to DHT: “Since DHT is a primary cause of androgenetic alopecia, saw palmetto could theoretically help slow hair-loss progression.” It’s commonly used in hair-loss shampoos aimed at both men and women with pattern thinning.

Biotin: “Biotin is a B vitamin essential for keratin production, which is crucial for healthy hair structure,” says Rambhia. While biotin deficiency is rare, supplementation only helps those who are actually deficient in this vitamin.

Keratin: Keratin is the protein that gives hair its strength and elasticity. “It doesn’t promote new hair growth, but it can temporarily strengthen and thicken existing hair strands,” explains Rambhia. It’s a common ingredient in strengthening shampoos that improve the look and feel of thicker hair.

Collagen: Collagen may supply amino acids needed for hair protein synthesis. However, Rambhia cautions that “the benefits for hair growth when used in shampoos are likely minimal,” since topical collagen doesn’t penetrate as deeply.

Aloe: A classic ingredient in shampoos targeting dryness and scalp irritation, aloe is beloved for its soothing, anti-inflammatory properties. According to Rambhia, “A calm, non-irritated scalp creates better conditions for optimal hair follicle function.”