Castor Seed Oil: What It Does for Lashes and Hair
What Is Castor Seed Oil?
Castor Seed Oil, listed on ingredient labels as Ricinus Communis Seed Oil, is cold-pressed from the seeds of the castor plant. The oil in our formulas is organically farmed, meaning no synthetic pesticides or fertilizers in the growing process.
Its defining characteristic is a high concentration of ricinoleic acid, a fatty acid that makes up approximately 90% of the oil's composition. This unusual fatty acid profile gives Castor Seed Oil its dense, viscous texture and its strong affinity for both hair fiber and skin. It absorbs slowly and creates a conditioning film on the surface it is applied to, which is why it functions effectively in both lash and hair formulas.
What Castor Seed Oil Does
Conditions and coats the lash or hair fiber. The ricinoleic acid in Castor Seed Oil forms a protective, flexible film over the surface of each hair or lash. This smooths the cuticle, reduces friction between fibers, and contributes to a softer, more manageable feel after use.
Supports moisture retention. Castor Seed Oil is an occlusive emollient that helps slow moisture loss from the hair fiber by creating a barrier on the surface. In lash formulas this supports flexibility and reduces brittleness. In hair formulas it contributes to lasting softness between washes.
Adds weight and flexibility without stiffness. In mascara specifically, Castor Seed Oil contributes to a formula texture that coats lashes without making them feel stiff or brittle after the product sets. It works alongside structural waxes to give lashes a conditioned rather than coated feel.
Where You'll Find It at True Colour Beauty
Castor Seed Oil appears in two formulas in the range.
The Volumizing Peptide Mascara uses organic Castor Seed Oil alongside Carnauba Wax, Olive Oil Unsaponifiables, and Pisum Sativum Peptide. In this formula it contributes to the conditioning feel of the mascara during and after wear, supporting lash flexibility alongside the structural wax ingredients.
The Rosemary Hair & Scalp Strengthening Oil uses Castor Seed Oil as one of its primary conditioning emollients, working alongside rosemary extract and other plant-derived oils to support scalp health and hair softness with each use.
