Show Notes
Episode 1: Andrew Huberman's Testosterone Protocol
In this episode, Seb breaks down Andrew Huberman's key testosterone optimisation recommendations against the peer-reviewed evidence. What holds up, what's overstated, and what the UK-specific version looks like.
Links mentioned:
- Full article: Andrew Huberman's Testosterone Protocol
- Testosterone blood test (Medichecks): [link]
- Magnesium glycinate guide: [/guides/magnesium-glycinate-guide]
- Sleep and testosterone guide: [/guides/sleep-testosterone-huberman-protocol]
Timestamps:
- 00:00 — Why Huberman's testosterone content matters
- 02:30 — Morning sunlight: what the evidence says
- 05:00 — Cold exposure and testosterone
- 07:30 — The supplement stack: zinc, magnesium, ashwagandha
- 10:00 — What's missing from his UK recommendations
- 12:30 — The bottom line
Full Script
So if you've been paying attention to the fitness and biohacking space over the last few years, you've probably heard Andrew Huberman's name. A lot. The Stanford neuroscientist has built a genuinely impressive audience by taking neuroscience, sleep science, and physiology and making it accessible. And one of his most popular topics? Testosterone optimisation.
His testosterone protocol has been discussed, implemented, and debated across gyms, podcasts, and Reddit threads. Which is great — more information about testosterone is useful. But it's also created a situation where people are treating his recommendations as gospel, sometimes without actually checking whether the evidence holds up.
So that's what we're doing today. [PAUSE] I'm Seb, and on this podcast we break down what actually matters for male performance optimisation — separating what the evidence supports from what sounds good but doesn't quite hold up.
Let's start with why Huberman matters here. He's not a testosterone specialist. He's a neuroscientist. But his approach to synthesising research and presenting it accessibly has made his work influential. So when he puts out a testosterone protocol, people listen. And honestly, some of what he recommends is solid. Some of it is overstated. Some of it works better in the US context than it does in the UK.
Let's work through it.
Morning Sunlight: The Foundation
Huberman's first recommendation is straightforward: get bright light exposure in the morning. Specifically, sunlight. Within the first hour of waking, get outside, get direct sunlight in your eyes — and he's particular about this — for about 10 minutes in summer or 20-30 minutes in winter.
What does the evidence actually say? [EMPHASIS] This one holds up pretty well. Light exposure in the morning regulates your circadian rhythm, and circadian rhythm disruption is genuinely associated with lower testosterone. Czeisler and colleagues have done good work on this. Morning light exposure increases alertness, improves sleep quality at night, and sleep quality is directly correlated with testosterone levels.
So does this improve testosterone directly? Not exactly. It improves sleep. And sleep drives testosterone. The testosterone elevation isn't from the light itself — it's from the circadian rhythm regulation leading to better sleep.
Is this important? Absolutely. [PAUSE] Most people aren't getting adequate natural light in the morning, especially in the UK where winter light is, let's be honest, pretty dim. So this recommendation is practically useful.
The caveat: Huberman sometimes presents this as if morning sunlight is this magic hormone optimizer. It's not. It's foundational circadian hygiene. It matters. But it's not going to increase your testosterone if your sleep is terrible, your stress is high, and you're in a caloric deficit.
Cold Exposure: Where It Gets Complicated
Next up is cold exposure. Cold showers, ice baths, that sort of thing.
Huberman's claim is that cold exposure increases dopamine acutely and increases testosterone. And here's where we need to slow down.
The acute dopamine increase? That's real. Exposure to cold water activates the sympathetic nervous system and increases dopamine. That's documented. People do feel more alert and energised after cold exposure.
Does it increase testosterone? [PAUSE] This is where the evidence gets murkier. There are some studies showing cold exposure can increase testosterone temporarily. But the effect is modest, it's situational, and it's definitely not the magic bullet that some versions of this protocol suggest.
The real issue with cold exposure for testosterone is this: you're getting an acute sympathetic nervous system activation. That's not the same as improving the chronic hormonal environment. If you're doing ice baths regularly, you're creating a chronically elevated stress signal. And chronic stress suppresses testosterone.
So cold exposure might give you a short-term boost. But if it's increasing your daily stress load, you're potentially working against yourself on testosterone.
Huberman's version of this — brief cold exposure, maybe a cold shower 30 seconds at a time — is probably fine. It's not going to hurt testosterone. But it's also not this powerful optimizer that some people think it is.
[EMPHASIS] The bigger lesson: don't do cold exposure expecting it to meaningfully change your testosterone. Do it if you like how it feels. That's the honest take.
The Supplement Stack: Zinc, Magnesium, Ashwagandha
Now we get to the supplements. Huberman recommends three specifically: zinc, magnesium glycinate, and ashwagandha. Let's assess each one.
Zinc. Zinc is required for testosterone synthesis. That's biochemistry — it's not up for debate. Deficiency in zinc reduces testosterone. So supplementing zinc if you're deficient will improve testosterone.
The question is: are you deficient? In developed countries, zinc deficiency is actually quite rare unless you have specific dietary restrictions. Most people eating reasonable amounts of meat, seafood, or nuts are getting adequate zinc.
What does supplementing extra zinc do if you're not deficient? The evidence suggests... not much. If you're already getting enough zinc, adding more doesn't meaningfully boost testosterone. You might see some minor improvement if you're on the lower end of normal. But we're talking small effects.
So Huberman's recommendation here is conditional. If you eat meat and you're not vegetarian, you probably don't need extra zinc. If you don't eat much animal protein, supplementing 15-30mg daily probably makes sense.
Magnesium glycinate. Magnesium is involved in hundreds of enzymatic reactions. And yes, it's involved in testosterone synthesis. But again, the question is dosing and context.
Magnesium deficiency is more common than zinc deficiency. A lot of people are sub-optimal on magnesium. And magnesium supplementation has solid evidence for improving sleep quality. And sleep quality is the real testosterone driver here.
Huberman recommends 300mg of magnesium glycinate in the evening. That's reasonable. It'll improve sleep for most people, which will improve testosterone. But the effect is indirect. The magnesium is helping sleep. Sleep is driving the testosterone improvement.
Ashwagandha. This is an adaptogenic herb that's been used in Ayurvedic medicine for centuries. Modern research on ashwagandha and testosterone shows... mixed results. Some studies show modest improvements in testosterone and strength. Other studies show minimal effect.
The best evidence? Ashwagandha does seem to reduce cortisol, which is an anti-testosterone hormone. So if you're stressed, ashwagandha might help by reducing stress hormones. But again, the testosterone improvement is secondary to stress reduction.
Huberman recommends 600mg daily. That's a reasonable dose based on the research. Will it meaningfully increase testosterone? For most people, probably a modest effect. If you're stressed and chronically elevated in cortisol, maybe more. If you're already managing stress well, probably minimal.
Sleep: The Actual Driver
Here's what Huberman gets really right, and what often gets lost in the conversation about his testosterone protocol: [EMPHASIS] sleep is the foundation.
Sleep deprivation directly reduces testosterone. This is well-established. Even one night of poor sleep reduces testosterone by 10-15%. Chronic poor sleep drops testosterone by 30% or more.
So the real testosterone protocol isn't morning sunlight plus cold exposure plus supplements. It's [PAUSE] actually getting seven to nine hours of quality sleep every night. That's the real driver.
And Huberman does emphasize this. But sometimes the conversation moves to the sexy parts — the cold exposure, the supplements — and the boring foundation of sleep gets deprioritized.
If you're getting five to six hours of sleep and you're taking ashwagandha thinking that's going to boost testosterone significantly, you've missed the actual lever.
What's Missing for the UK Context
One thing Huberman's protocol doesn't adequately address is the UK-specific context around vitamin D. In winter in the UK, sunlight is dim and brief. Most people aren't getting adequate sun exposure for vitamin D synthesis. And vitamin D is genuinely important for testosterone.
Studies show that vitamin D deficiency is associated with lower testosterone. Supplementing vitamin D in deficient populations improves testosterone.
So if you're in the UK, especially in winter, vitamin D supplementation — 2000-4000 IU daily, or 50-100 mcg — is worth adding to the protocol. Get a blood test to check your level. If you're below 30 ng/mL, you're deficient. Supplementation makes sense.
Huberman doesn't emphasize this enough, and it's a real gap in his UK recommendations.
The Bottom Line
Huberman's testosterone protocol has useful elements. Morning light exposure is solid circadian hygiene. Magnesium and potentially ashwagandha can support sleep quality. Zinc supplementation makes sense if you're not getting enough from food.
But the protocol's effectiveness comes from the foundation, not the add-ons. Sleep is the real driver. Then stress management. Then training and nutrition.
The supplements, the cold exposure, the morning sunlight — these are optimizations around a foundation that needs to be solid first. If you're not sleeping well, you're stressed, and you're not training or eating properly, taking ashwagandha isn't going to meaningfully change your testosterone.
What should you actually do? [PAUSE]
First, get a testosterone blood test. You need to know where you actually are. If you're optimizing testosterone, you should have a baseline and a way to measure progress. [EMPHASIS] Most people never get their testosterone tested. You can't optimize something you're not measuring.
Second, sort out sleep. Seven to nine hours. Consistent schedule. Cool, dark room. This is the foundation. Everything else is built on this.
Third, manage stress. Chronic stress is genuinely anti-testosterone. Whether that's meditation, exercise, social connection, or something else — find what works for you.
Fourth, train with intensity. Resistance training drives testosterone. Especially compound movements. Squats, deadlifts, bench press. If you're not doing resistance training, this is the biggest lever you're missing.
Fifth, eat adequate protein and calories. If you're in a massive caloric deficit or you're not eating enough protein, your testosterone will suffer. Aim for 0.8-1g of protein per pound of body weight.
And then, if you want to optimize further, the supplementation makes sense. Magnesium for sleep. Vitamin D if you're in the UK in winter. Zinc if you're not eating enough animal protein. Ashwagandha if you're dealing with chronic stress.
But let's be clear: the supplements are the 10% optimization. The foundations are the 90%.
[EMPHASIS] That's what Huberman's protocol actually tells us, once you separate the neuroscience from the hype.
If you want the full deep-dive on the evidence and the specific mechanisms, check out the full article on the site. We've got the studies referenced, the dosing recommendations, and the specific protocols broken down further.
And if you found this useful, subscribe. Share it if you know someone optimizing their testosterone. Check the show notes for links to the articles and the testing resources mentioned.
Thanks for listening.
About the Show
The Male Optimal Podcast breaks down research and recommendations for male performance optimisation. Each episode covers practical science, separates evidence from hype, and gives you the actual tools to implement.
Hosted by Seb, who writes on applied physiology and performance science.