Warming Sensation in Eye Serum Formulation

Okay, I understand you've successfully made the eye serum following the advice, but you experienced a slight warming sensation around the eyes and are wondering if it's from the Orange Peel Extract.

Here's the likely explanation:

It's less likely that the Orange Peel Extract is causing the warming sensation. While some extracts can cause irritation, a warming feeling is more commonly associated with other ingredients in your formula.

The most probable cause for the slight warming sensation is the Vitamin B3 (Niacinamide). Niacinamide is known to sometimes cause a temporary flushing or warming effect on the skin, especially in sensitive areas like around the eyes or at concentrations of 2% or higher. You used 2% Niacinamide in your formula.

Another ingredient that could potentially contribute to a warming sensation, though less likely than Niacinamide, is Mild Preserved (Ethylhexylglycerin/Caprylyl Glycol), although this is less common at the concentration you used (0.8%).

If the sensation is just warmth and not accompanied by significant redness, itching, or prolonged irritation, it might be a normal, temporary reaction to the Niacinamide. However, the eye area is very sensitive, so if the warming is bothersome or you experience any signs of irritation, you might consider reducing the concentration of Vitamin B3 or Mild Preserved in future formulations.