Analysis of the Formulation and User Feedback

Based on the discussion and the provided formulation, here's an analysis regarding the warming sensation and the friend's reaction:

Warming Sensation

The warming sensation experienced upon application could be attributed to two potential ingredients:

• Cyclomethicone: As explained by the staff, this ingredient can form a temporary film on the skin, which might trap the body's natural heat, leading to a feeling of warmth until the ingredient evaporates. This is generally not harmful.
• Vitamin B3 (Niacinamide): According to user chalermlap, Vitamin B3 (and other B vitamins like B5 and B12) can cause a warming or flushing sensation, especially at higher concentrations. This feeling typically subsides shortly after application. Reducing the percentage of Vitamin B3 was suggested if this sensation is not desired.

Friend's Allergic Reaction/Breakouts

The breakouts experienced by the friend are most likely caused by the Silicone ingredients in the formula:

• Cyclomethicone and Silicone Gel Base: Both chalermlap and cosmeceutical7 identified silicones as common culprits for sensitive, easily irritated, or acne-prone skin. Silicones can potentially clog pores, leading to breakouts.

Other potential ingredients mentioned, though less likely than silicones, include:

• Alpha Arbutin: Suggested as a possibility if silicones are not the cause.
• Nanowhite: Specifically the Glutathione component within Nanowhite was mentioned as potentially causing itching and clogged pores.

Recommendations for Adjustment

To address the friend's breakouts for future production, the primary recommendation based on the feedback is to reduce or remove the Silicone components (Cyclomethicone and Silicone Gel Base) from the formula, as they are the most suspected cause for sensitive or acne-prone skin.

If the warming sensation is a concern for users, reducing the percentage of Vitamin B3 could help mitigate this effect.