Scalp serums are leave-in treatments you apply to the scalp, usually daily, and most promise thicker-looking hair over a few months. The key word is looking. Many work on how full hair appears and how much breaks or sheds, rather than on growth itself.

The Ordinary's Multi-Peptide Serum for Hair Density is the simple, concentrated option, made to help hair look thicker and fuller. Nécessaire's Scalp Serum uses five percent Capixyl and hyaluronic acid, quick drying with no residue. Vegamour's GRO serum is vegan, and the brand says it improves the look of density and reduces shedding in as soon as 90 days. Caudalie's Hair Density Serum is made for all types of thinning hair.

Moroccanoil's Revitalizing Scalp Tonic is a weightless leave-in spray, and the brand reports clinical results for reduced fallout and shedding. OUAI's Hydrating Scalp Serum balances and hydrates, treating the scalp like skin. Kérastase's Genesis serum is silicone free and strengthens weak hair against breakage, and Oribe's Hair Alchemy serum strengthens brittle strands and improves elasticity.

Use serums on a clean, dry scalp, part your hair in sections, and apply directly to the skin rather than the hair. Take a photo of your part in the same light every month. Changes are slow enough that you will not notice them in the mirror day to day, and a monthly photo is the only honest way to know whether something is working.

A scalp massager is the most pleasant five minutes in any hair routine. It loosens buildup, helps shampoo reach the scalp and feels wonderful, and a little research suggests regular scalp massage may help hair look thicker over time, though the studies are small.

Briogeo's Scalp Revival massager is hand-held, with soft bristles, made to increase circulation and support a healthy scalp. Ceremonia's massager gently exfoliates and massages, and it is the prettiest of the group. Sephora Collection's Silicone Scalp Massager is hygienic and works wet or dry, and Bread Beauty Supply's Scalp-Thingy is a 100 percent silicone massager designed to boost blood flow and remove buildup. Dr. Groot's Scalp Massager Brush has soft, flexible silicone bristles for a comfortable massage.

Use one in the shower with shampoo, moving in small circles from the hairline back to the crown, or on a dry scalp with your oil before washing. Gentle pressure is enough. You are massaging skin, not scrubbing a pan, and pressing too hard can irritate the scalp you are trying to look after.

Pairing is where the routine comes together. Oil on a dry scalp, five minutes with the massager, twenty minutes to rest, then shampoo twice to lift the oil out. Do it on a Sunday evening with a podcast and it stops feeling like a chore.

Hair grows slowly, roughly half an inch a month, so any routine needs at least three months before you judge it. Keep it simple and consistent: a scalp oil or pre-wash once or twice a week, a serum daily if you use one, and a gentle shampoo.

If you are losing hair suddenly, in patches, or after an illness, a new medication or a pregnancy, see a dermatologist. Hair loss has many causes, including thyroid issues and low iron, and the right fix depends on the cause. Oils and serums are a lovely way to care for your scalp, but they are not a substitute for a diagnosis.