Silybum Marianum Extract
Explained
This ingredient comes from the milk thistle plant. It is a skin conditoning ingredient that helps skin stay soft and hydrated.
The star compound in this extract is a group of flavonolignans collectively called silymarin, with silybin being the most studied.
Research shows silybin extract can protect skin from UV-induced oxidative stress and also works to calm inflammation.
There's also growing interest in its potential for acne-prone skin. One 12-month study on over 50 subjects using topical Silybum Marianum Extract found a ~60% reduction in acne lesions over the course of a year.
More recently, a 2025 study found silybin significantly boosted collagen III and hyaluronic production in skin tissue with results comparable to retinol; please know retinol is still the gold standard and silybin research has a long ways to go to confirm whether it can replace retinol.
In terms of tolerability, one large study of over 4,000 participants rated this ingredient tolerance as "good" or "very good" in about 95% of participants.
See all 147 products with Silybum Marianum Extract
