This is a Huberman AMA, which means it's a grab-bag of topics. But there's a thread running through all of it that I find genuinely interesting: cold therapy keeps showing up as a solution to problems that, on the surface, have nothing to do with each other. Skin aging. Mental clarity. Motivation. Resilience. The mechanism shifts depending on the question, but the tool stays the same.
The core claim here is that deliberate cold exposure—45 to 50 degrees Fahrenheit, one to three minutes—produces a neurochemical response that lifts alertness and mood well beyond the session itself. That's the cold therapy piece. The skin health piece runs parallel: collagen supplementation, mineral sunscreen, red light therapy. Huberman isn't claiming cold water gives you better skin. He's presenting two separate protocols that together address how we age visibly and how we feel mentally.
The cellular picture is more interesting than either claim alone. We have a 2021 paper in our database on Afadin—a protein expressed in brown fat—that shows cold exposure directly upregulates thermogenic capacity at the cellular level. When you expose yourself to cold, you're not just shocking your nervous system awake. You're signaling to your fat cells to become metabolically active. That process generates heat, yes, but it also has downstream effects on inflammation, circulation, and tissue perfusion—all of which matter for skin health in ways the article doesn't mention.
In other words, cold therapy might be supporting skin health through a back door: better circulation, lower systemic inflammation, improved metabolic function. The collagen you're supplementing has a better environment to work in.
On the cold therapy and alertness claim, there's broad consensus. Norepinephrine, dopamine, the sympathetic spike — that's well-documented and consistent across the research we've indexed. Where it gets more contested is the direct skin benefit of cold exposure. Some researchers point to vasoconstriction reducing puffiness and inflammation; others argue that effect is transient and cosmetically overstated. The honest answer is that cold's skin benefits are largely indirect, and Huberman is careful not to overclaim here.
On collagen supplementation, the dose range he cites — 5 to 30 grams per day — is consistent with what the clinical literature supports, though the effect sizes are modest. It's a tool worth using, not a miracle.
Run these protocols in parallel, not as alternatives. Cold plunge in the morning for the neurochemical benefits — clarity, alertness, emotional resilience. Take your collagen with vitamin C at breakfast, because ascorbic acid is a cofactor for collagen synthesis that most people skip. Protect your skin from sun daily, not just when you remember. And if you're already using red light therapy, keep it consistent — the research on infrared and skin texture rewards regularity over intensity.
The most underappreciated overlap here is the one Huberman mentions only in passing: deliberate heat exposure for depression. We're funding research on this, and what's emerging is that heat produces an antidepressant effect lasting up to six weeks from a single session. Cold does something similar but faster and shorter. Contrast therapy — heat followed by cold — may be doing both simultaneously. The skin, the mood, the metabolic activation: they're all downstream of the same oscillation. You're not treating body parts. You're tuning a system.