Do I need to patch test homemade products?
Short answer
Always. Test every new product on the inner elbow or forearm for 24–48 hours before first use.
Explanation
The skincare formulas each end with safety notes, and patch testing appears throughout. Apply a small amount to the inner elbow or forearm and wait 24–48 hours, or the full 48 hours for atopic or very reactive skin. Stimulating products such as the firming gel or caffeine eye products can cause mild warmth or tingling, which is normal. Rinse off if burning is strong or lasts.
What to do
- Patch test each new batch, not just each new recipe.
- Introduce acid products (AHA/BHA) gradually and keep them away from the eye area.
Source: The Big Book of Homemade Skin Care — Safety notes in each formula