Hair Products: What Ingredients Actually Do for Your Hair

Most people buy hair products based on how they smell, how they make the hair feel immediately after use, or what a marketing claim promises. None of these are particularly reliable guides to what actually works for hair health over time.

Shampoo: What to Look For Beyond Lather

A shampoo's primary job is cleaning the scalp. Sulfates like SLS are effective cleansers but can strip the scalp of natural oils. Sulfate-free shampoos use milder surfactants that are gentler on color-treated hair and sensitive scalps. For people who use heavy styling products, a clarifying shampoo used once every few weeks removes buildup that milder formulas cannot shift.

Conditioners and Masks: What They Are Actually Doing

Conditioners primarily deposit positively charged molecules onto the negatively charged hair shaft, smoothing the cuticle, reducing static, and improving slip for detangling. They do not repair hair at a structural level. Hair masks with higher concentrations of conditioning agents and hydrolyzed proteins provide more intensive temporary improvement. Look for hydrolyzed proteins (small enough to penetrate the shaft), ceramides, and penetrating oils like coconut or avocado rather than purely coating oils like mineral oil.

Bond Repair Products: Do They Work?

Bond repair technology, popularized by products like Olaplex, works by reconnecting disulfide bonds within the hair cortex broken by chemical damage from bleach, color, and heat. Multiple independent studies have confirmed the efficacy of this technology for chemically damaged hair. Using a bond repair treatment on hair that has no significant chemical damage produces minimal benefit.

Hair Growth Products: What Actually Works

Minoxidil is the most studied topical ingredient for hair regrowth. The 5 percent concentration produces significantly more regrowth than 2 percent in studies. Results take three to six months to become visible and stop when treatment is discontinued.

Rosemary oil has some evidence, including a 2015 study comparing it to 2 percent minoxidil with comparable results at six months. The caveat is that the comparison was to the weaker 2 percent formulation. Rosemary oil is a reasonable option for mild hair thinning but minoxidil has a much larger evidence base.

Caffeine applied topically has been shown to stimulate hair follicles and counteract some DHT effects. Redensyl, a newer ingredient, has preliminary evidence comparable to minoxidil though studies have industry connections that warrant caution.

Heat Protection: Non-Negotiable for Styled Hair

Heat protectants create a coating over the hair shaft that distributes heat more evenly and raises the temperature at which structural damage occurs. No heat protectant makes high-heat styling harmless, but they significantly reduce damage at moderate temperatures. Applied every single time before any heat tool.

Scalp Care: The Underattended Category

Scalp exfoliation with scrubs or salicylic acid treatments removes buildup, dead skin cells, and excess sebum that can clog follicles. Used once or twice a week, they improve scalp health and product absorption. Scalp massage for three to four minutes daily has evidence for improving hair thickness through increased blood circulation to follicles.