Stinging Sensation from Acne Treatment Formulation

Question

I have a formulation with the following ingredients and percentages:

B3: 5%
ZnPCA: 1%
Ichthammol: 1%
MicroKill: 1%
Glycerin: 2%
Xanthan: 0.9%
1,2 Hexanediol: 3%
prenoxySA: 0.3%
LipidSoft-F: 4%
Water: 81.8%

After using it for 7 days, I feel a stinging sensation on my face. I would like advice on which ingredient might be causing this, especially when used on inflamed acne. Thank you.

MySkinRecipes Expert · Accepted Answer

Based on the formula you are using and the stinging sensation you are experiencing, especially on inflamed acne, several ingredients could potentially be contributing to this reaction.

Here are the ingredients in your formula that might be causing the stinging:

Safe-B3™ (Niacinamide): While Safe-B3™ is a high-purity form designed to minimize flushing, using Niacinamide at 5% can still cause a warming or tingling sensation in some individuals, particularly when applied to sensitive or inflamed skin like acne.
Phenoxyethanol SA: This is a preservative blend containing Phenoxyethanol, Caprylyl Glycol, and Sorbic Acid. Sorbic Acid, in particular, is known to sometimes cause stinging or burning sensations, especially on skin with a compromised barrier, such as inflamed acne.
1,2-Hexanediol: At 3%, this ingredient acts as a solvent and a penetration enhancer. While not typically irritating on its own, it can help other ingredients penetrate the skin more effectively. On inflamed skin, this increased penetration could potentially intensify the sensation or irritation caused by other active ingredients or preservatives in the formula.
Ichthammol: Although used for its anti-inflammatory and antibacterial properties, any active ingredient can potentially cause a sensation on highly inflamed or sensitive skin.

Inflamed acne means your skin barrier is compromised, making it more susceptible to irritation and stinging from ingredients that might be well-tolerated on healthy skin.

It is difficult to pinpoint the exact culprit without testing, but Niacinamide and the preservative blend (Phenoxyethanol SA, specifically the Sorbic Acid component) are common causes of stinging sensations, which can be exacerbated by the penetration-enhancing effect of 1,2-Hexanediol on inflamed skin.

Consider reducing the frequency of use or applying a smaller amount to the affected areas. If the stinging persists or worsens, you may need to adjust the formula or discontinue use on inflamed areas.