Happy Tuesday!
I sat down at my desk the other afternoon, feeling like I had been hit by a truck.
Long day. Brain fog. Zero motivation to do anything productive.
I grabbed my CO2 inhaler, strapped it on, dialed it to about 5%, and sat there for 10 minutes.
By the time I took it off, I felt like a different person. Clear head. Energy back. Ready to go.
This little device has become one of my non-negotiables. And today I want to tell you exactly why.
I just dropped a brand new video breaking down the complete science behind CO2 therapy. Everything I'm going to cover in this email and more. If you want to watch it, here are the links.
I know this isn't a peptide topic, but stick with me because this one actually amplifies everything else you're doing, including your peptides!
What Is CO2 Therapy?
When most people hear "carbon dioxide," they think waste gas.
That's only half the story.
Carbon dioxide therapy involves inhaling small, controlled amounts of CO2-enriched air through a device. Typically, between 2% and 7% CO2.
The concept goes back over a century. A Yale physiologist named Yandell Henderson discovered it actually drives circulation and oxygen delivery throughout the body.
Henderson invented a device called the H-H Inhalator that used a mixture of 5 to 8% CO2 in oxygen to resuscitate drowning victims, overdose patients, and even newborns who weren't breathing. By 1928, fire departments across America were using it. Henderson credited it with saving several hundred babies.
Fast forward to today.
Companies like Carbogenetics have brought this concept into the consumer space with affordable devices you can use at home.
You hook up a SodaStream CO2 canister, strap on the mask, dial in your percentage, and breathe.
How It Works
The core mechanism is something called the Bohr Effect.
Your blood oxygen saturation is already around 96 to 98%, no matter how you breathe.
The problem isn't getting oxygen into your blood. It's getting oxygen from your blood into your tissues. That's where the magic happens.
When you inhale CO2, it enters your bloodstream and slightly lowers the pH.
That pH shift loosens hemoglobin's grip on oxygen. More oxygen is released into your muscles, brain, and organs.
Think of hemoglobin like a delivery truck.
It picks up oxygen in the lungs just fine. But it doesn't always want to drop it off at the destination. CO2 is the key that forces the truck to open the doors and unload.
On top of that, CO2 is one of the most potent vasodilators known to science, especially in the brain.
At just 5% CO2, cerebral blood flow increases by roughly 50%.
A landmark 2008 study found that carbogen (a CO2/oxygen mixture) increased brain blood flow, whereas pure oxygen alone decreased it.
You also get parasympathetic nervous system activation.
I've tracked this personally with my Oura ring. The nights after I use my CO2 inhaler, my HRV is consistently better than the nights I don't.
What the Clinical Data Shows
I went deep into the published research for the video. Here are the highlights that matter most.
Wound Healing. A 2020 double-blind RCT in 57 diabetic chronic wounds. The CO2 group saw 96% reduction in wound surface area and 99% reduction in volume. The control group saw just 25% surface reduction. 67% of CO2 wounds healed completely. Zero healed in controls.
Tumor Oxygenation. The ARCON protocol combined carbogen with radiotherapy for laryngeal cancer. A Phase 3 trial of 345 patients found 100% regional control in hypoxic tumors with ARCON versus 55% with radiotherapy alone.
Peripheral Circulation. A randomized double-blind trial in claudication patients. After 18 days of transcutaneous CO2, total walking distance increased 66%. Pain-free walking improved 73%. Results held at 3 and 12 months.
Hearing Recovery. A study of 202 patients with sudden hearing loss. Carbogen plus steroids achieved 68% recovery versus 52% with steroids alone. In severe cases, the gap widened to 71% versus 43%.
Muscle Recovery. CO2 upregulated PGC-1 alpha, SIRT1, and VEGF. Sound familiar? That's the same pathway SLU-PP-332 targets. Increased mitochondrial number, capillary density, and induced fast-to-slow fiber type switching in animal models. In humans, CO2-enriched cold-water immersion significantly improved muscle oxygenation compared with plain cold-water immersion.
My Personal Protocol
I've been using this on and off for about 6 months. Here's what works for me.
Morning (5 minutes at 2 to 4%). I do this before my coffee. It's like flipping a switch for alertness. If you struggle with morning grogginess, this will change your life.
Pre-Workout (10 minutes at 5%, about 30 minutes before training). This is my favorite use case. The vasodilation primes blood flow and oxygen delivery. You will feel a better pump. You will feel better endurance. It's noticeable from the first session.
Afternoon Reset (5 to 10 minutes at 5%). If I hit that 2 PM wall and my brain starts to fog over, this is better than another cup of coffee. No jitters. Just clarity.
Important. Do not use this right before bed. It can be stimulating. I typically stop by 4 or 5 PM.
Start at 1 to 2% for your first few sessions regardless of what time you use it. Build up gradually. Listen to your body.
Final Thoughts
I use the CO2 Inhaler from Carbogenetics.
I want to be transparent. I met the owner at a conference, tried his products, and became a believer through my own experience.
He also just released a book called The Carbonated Body, which I'd highly recommend if you want to go deeper into the science.
As biohacking devices go, this is incredibly affordable compared to things like hyperbaric chambers, red light panels, or even high-end saunas. And I use it more consistently than almost anything else I own.
Grab the CO2 Inhaler here and use my code HUNTERW for 15% off.
If we can increase peripheral oxygen delivery to tissues, that will only increase the efficacy of the peptides you're already running.
Better blood flow means better delivery. Better delivery means better results. Think of this as the multiplier for everything else in your stack.
Thank you guys so much for the continued support.
Whether you watch the videos, read these emails, share them with friends, or hang out with us in the Axion Collective every Thursday night, it all means the world to me and goes a long way toward allowing me to keep bringing this content to you!
Best,
Hunter Williams
Further Reading