Hair Oil Blend Builder

How it works

The builder scores each of the 30 carrier oils in our database against your porosity and what you want the oil to do, then mixes the top two to four into a bottle of the size you choose. Everything runs in your browser.

1. Weight matched to porosity

Porosity describes how easily water gets into the hair and how fast it leaves. Low-porosity hair has a tightly closed cuticle, so heavy oils sit on top and feel greasy — the builder favors light oils such as grapeseed, jojoba and argan, and never picks a heavy oil for low porosity. That is also how it answers the most common question we get, the best oil for low porosity hair: something light, used sparingly on damp hair. High-porosity hair loses water quickly, so medium and heavy oils that slow that loss score higher.

2. The goal decides the rest

Each oil is tagged with what it is good for — shine, sealing, scalp massage or pre-poo. A match adds points. For a pre-poo, and for sealing high-porosity hair, oils with evidence that they enter the hair shaft get extra weight. Only coconut oil is marked as shown to penetrate; olive, avocado and babassu are marked “may partly penetrate” because the evidence is limited.

3. Sensible proportions

The top oil becomes the base (40–60% of the bottle) and the others fill smaller shares. Very thick or strong-smelling oils are capped — castor at 25%, black seed and tamanu at 20%, neem at 10% — so the blend stays easy to spread. Two oils with the same INCI name, such as castor and Jamaican black castor, are never paired.

4. Essential oils, carefully

If you add an essential oil, it is limited to 2% of the blend, or 1% for peppermint and tea tree. Drops are estimated at about 20 per milliliter, a common dropper approximation — real droppers vary. These are cosmetic add-ins, not treatments.

Limits

• Oils don't add moisture on their own; they slow its loss. Use them after a water-based product.
• Oils are not heat protectants, whatever their smoke point.
• Nut-derived oils are flagged, but cross-reactions are not always known. If you have allergies, ask your allergist.
• Shelf lives are typical values for opened oils stored cool and dark — trust your nose.