Scalp serums, as a category, tend to fall into two camps.

One is the clinical route — minoxidil, peptides, growth factors, ingredients designed to intervene. The other is the marketing route — a few drops of rosemary oil in a base of cheap carrier, sold with the word "rosemary" in bold and not much else to back it up.

The Limited Hop-Infused Growth Serum is a third thing.

It's a traditional scalp oil, built from six whole-plant ingredients, that takes itself seriously without getting clinical. The hero ingredient is hops — specifically, fresh, locally grown, Salmon-Safe certified hops. You probably know hops from beer. Fewer people know that hops have a long history in European herbal medicine for skin and hair, or that the compounds in the flowers have been studied for their antibacterial, antifungal, and mildly estrogenic properties — all of which are relevant to scalp health, oil balance, and the hormonal side of hair thinning.

Hops is joined by two of the most well-documented Ayurvedic hair herbs in the world. Amla (Indian gooseberry) is one of the highest natural sources of vitamin C and has been used for centuries to support hair density, slow premature graying, and calm an inflamed scalp. Bhringraj translates roughly to "king of hair" and has been the go-to tonic for scalp circulation and follicle support across Ayurvedic traditions for as long as those traditions have existed. Cacao extract adds antioxidants and helps stimulate circulation. Bitter orange flower extract finishes with a light neroli note that keeps the overall scent grounded rather than medicinal. The entire formula is carried in golden organic jojoba — a wax ester that mirrors the scalp's own sebum, which is why it absorbs instead of sitting.

The ritual is simple. Part your hair, apply a few drops along the scalp, and massage for two to three minutes. Leave on for at least 15 minutes — overnight, if you want the full effect. Double-cleanse with your shampoo of choice. Once a week is enough.

This one is limited. Under Luna makes it in small batches when the hops are fresh and available, which is the entire point. Hops lose potency quickly once they've been dried and stored — fresh-infused is the version that actually does something.

2 fl oz in recyclable glass.

Aromatics: hops, cacao, neroli.