Shereene IdrissBoard Certified Derm, Founder and Chief Nerd

YouTube Channel

30 Jan 2026 · 1 min

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0:43

A short YouTube clip (dermatologist monologue) discussing effects of fatty acids on the skin barrier. The speaker explains that oleic acid increases penetration and can disrupt the stratum corneum, cites an optimal linoleic:oleic ratio of ~3:1 for healthy skin, gives beef tallow’s composition (linoleic 2–3%, oleic ~45%), and warns this imbalance can worsen acne and irritation for acne-prone, dry, or irritated skin.

Questions this video answers

3:1

2–3%

≈45%

Chapters

It can help repair your skin barrier and keep your skin happy and healthy. This is where problems begin, starting in the epidermis on the uppermost layer, also known as the stratum corneum. Because oleic acid enhances the penetration with other actives and breaks down that stratum corneum lightly, and that can make you more irritated. But the bigger problem is this. The optimal ratio of linoleic acid to oleic acid in skin and healthy skin is 3 to 1. Then beef tallow. Linoleic acid is only present at 2 to 3%, whereas oleic acid is FL flooding it at 45%. And when that disruption happens, your face is going to blow up, your acne is going to get worse. If you're prone to acne, and if you're dry and dehydrated and prone to irritations, your life just got Leave your questions below.