TheActives Tranexamic Acid 3% + Butylresorcinol 0,1% Versus Somethinc Glass-C 12% Vitamin C Serum

In head-to-head biochemical assays, it outperformed kojic acid, arbutin, and even hydroquinone at slowing melanin production.

Clinically, 0.1% has shown to improve melasma visibly after just 4 weeks. Another liposome-encapsulated version performed similarly well and an Indian study on 0.3% showed significant melasma reduction over 8 weeks with no adverse events reported.

This ingredient is generally well-tolerated. A very small amount of people have experienced mild dryness or peeling at a higher concentration (0.3%).

According to a manufacturer, this ingredient is sensitive to air. Good formulations should account for this to keep your rucinol effective.

Be sure to also check out Thiamidol, another "hydroquinone alternative".

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.

One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).

Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.

You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.