Analysis of Formulation Causing Redness

Subject: Analysis of Formulation Causing Redness

Thank you for providing your formulation and details about the allergic reactions experienced by some users.

Based on the ingredients listed and the symptoms (redness after about a week of use in a few individuals), the most likely ingredient causing irritation is Laureth-23.

Here's why:

• Laureth-23 is primarily used as an emulsifier to mix oil and water phases. Your formula appears to be mostly water-based with no significant oil phase.
• Including an emulsifier when there's nothing to emulsify is unnecessary and can increase the potential for skin irritation, even with a relatively mild surfactant like Laureth-23, especially at a 3% concentration in a formula without oils.
• As suggested by cosmeceutical7 in the forum thread, removing Laureth-23 is a logical step to reduce the risk of irritation in this specific formula.

Other ingredients are less likely culprits:

• Ethylhexylglycerin at 0.5% is a mild ingredient and rarely causes sensitization.
• Niacinamide at 2% is generally well-tolerated, although higher concentrations can cause flushing. Redness appearing after a week suggests irritation rather than initial flushing.
• Propylene Glycol at 10% can sometimes cause irritation in sensitive individuals, but Laureth-23 is a stronger suspect given its potentially inappropriate use in this formula.
• Natural extracts like Sea Kelp, Snail Secretion, and Tomato extract are also potential allergens, but Laureth-23 is a more common source of formulation-related irritation in this context.

Recommendation:

Consider removing Laureth-23 from the formulation. Since there is no oil phase, it is not needed for emulsification, and its removal should help reduce the risk of irritation.

Please note that individual skin sensitivities vary, and it's always possible for someone to react to any ingredient. However, based on the formula structure, Laureth-23 is the most probable cause of the observed redness.