The Scalp Serum

Matches niacinamide and glycerin but completely lacks the acetyl tetrapeptide-3 (the hero anti-thinning peptide) and hyaluronic acid, so it's not treating the scalp the same way.

Shares niacinamide and panthenol, but this is a leave-in styling cream focused on hair fiber (wheat protein, castor oil) rather than scalp treatment, and lacks the peptide and hyaluronic acid.

Shares niacinamide and panthenol but is missing the acetyl tetrapeptide-3 and hyaluronic acid that make the Nécessaire serum a scalp-treatment, replacing them with plant extracts and acids instead.

Shares only niacinamide in a formula built around surfactants and essential oils for an anti-hair-loss wash, missing the peptide, panthenol, and hyaluronic acid entirely.

Only overlap is glycerin and acetyl tetrapeptide-3, but it's missing niacinamide, panthenol, and hyaluronic acid entirely, relying instead on plant-derived peptides and callus extracts.