Walnut (Juglans regia) extract is derived from the nut, shell, or leaves and is used in skincare for its antioxidant polyphenols, tannins, and as a physical exfoliant when ground shell particles are included. It is also used in some products for its mild astringent and conditioning properties.
| Reported effect | How often | Notes |
|---|---|---|
Mechanical irritation / micro-abrasions | Common | Ground walnut shell particles have irregular edges and can cause microtears in the skin barrier when used as a physical scrub. |
Skin irritation or redness | Uncommon | Tannins and polyphenols may cause mild irritation, especially on sensitive skin. |
Allergic contact dermatitis | Rare | Tree-nut-allergic or sensitized individuals may react; patch testing advised. |
Skin staining | Rare | Juglone and related compounds in walnut hull can temporarily stain skin a brown/yellow tint. |
Photosensitivity | Very rare | Isolated reports; clinically limited evidence. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.