For men and women with fine, flat or weak-feeling hair who want a fortifying shampoo, either on its own or as the first step before a leave-on scalp product. It's an at-home product and needs no professional application.

Its role is narrower than a typical thickening shampoo: Phyto designed it to tone and prepare the scalp before a leave-on scalp product, using a mild cleansing base that won't strip away what you apply next, plus red algae extract so hair feels thicker straight away. Used on its own, it's a gentle, fortifying shampoo for fine or weak-feeling hair.

Apply to a wet scalp and massage in gently, then rinse. Repeat the application, this time leaving it on for about 2 minutes before rinsing thoroughly. Use it as a daily shampoo on its own or before a leave-on scalp product.

• Sarcosinate/betaine-based cleansing system is generally gentler than sulfate shampoos, which matters if you follow it with a leave-on scalp product.
• Red algae extract's coating effect can make hair feel thicker between washes, a cosmetic benefit worth knowing going in.
• Works as a daily shampoo or as a prep step, so there's no need to buy a separate everyday shampoo.

• The guarana, red algae and horsetail extracts are add-ons in a standard surfactant base, not the majority of the formula, so don't expect a mostly botanical shampoo.
• It's a cosmetic shampoo: it changes how hair looks and feels, not how much hair you have.
• Premium pricing relative to mainstream fortifying shampoos for what is, ingredient-wise, a conventional gentle cleanser with a few added extracts.