Andrew Huberman on Peptide Stacking, GLP-1s, and the Gila Monster That Changed Weight Loss

Andrew Huberman makes a habit of collapsing worlds that are usually kept apart, explaining, for example, how willow bark became aspirin. Or the venom of a desert lizard evolved into Ozempic. What begins as field biology ends up, after enough isolation and replication, on a prescription pad.

On this week’s episode of the goop podcast, Gwyneth sits down with Huberman, a Stanford neurobiologist whose podcast has become required listening in certain corners of the wellness-industrial complex, to talk about that uneasy border between nature and pharma. They move from GLP-1 drugs to peptide stacking to the ways in which ancient plant compounds are refined, standardized, and sold back to us as modern salvation.

And yet Huberman’s refrain is almost stubbornly plain. In a culture that chases optimization with the fervor of a hedge fund chasing yield, he returns to the unsexy basics: early light, adequate protein, heavy lifting, a defined eating window, a gut that functions as it should. The future may arrive in injectable form. The foundation, he argues, still does not.

Gwyneth: I'm thrilled to have you on the podcast. I am a big fan of your work, and obviously, your deep dives are legendary. When you started doing your podcast, and I started listening to it, it was really amazing to kind of hear all of the rigorous science behind all of the things that I sort of was instinctively feeling and hearing around health and biology and sort of what the body is capable of when you give it the right conditions.

My son, who's 19, is obsessed. He quotes you all the time.

Andrew: Well, thanks for the kind words. I'd never done anything public-facing. It's been fun. But really hard. I was not prepared for it.

GP: You weren't? What was hard or what is hard?

AH: People kind of want to keep you where they found you. I think people are like, "Oh, this science professor is talking about biology." I brought former Mr. Olympia champion Dorian Yates, the six-time winner of bodybuilding’s top professional title, on the podcast because he has the best training tools, and he doesn't care if there's a double-blind placebo-controlled study for that. We just wanted to showcase that knowledge. People see that, and then they go, "Wait, what's happened to your podcast?"

But I think that the sand between the silos is really starting to show up—and it's super exciting.

GP: It is. And I think that's also where the consumer, in having this new sort of agency around their health and ideas, is really forging ahead in that sense. In the early days of goop, people would say, "Why are you writing a piece on acupuncture or something in that world?"

The other part is, if there's a modality that is generations and generations old, there's going to be something there. I'm not saying we don’t need double-blind, placebo-controlled studies, especially when it comes to medications. But there's always somebody who stands to benefit from that monetarily, while somebody who goes out of their way to study acupuncture and puts the science behind it–nobody's going to patent that. It's not going to become a three-billion-dollar drug.

AH: Oh, absolutely. And I think that there are two areas that I learned about recently through the podcast that have completely reframed the way I think about traditional and modern medicine.

I had a guy on the podcast, Chris McCurdy, who's a researcher down in Florida. He studies Kratom, a plant that increases alertness [at lower doses] and can also be a mild sedative [at higher doses]. It's used in Indonesia; people chew on it there, and it's just part of the culture. Here, it's been used to create these very potent chemical derivatives that act like opioids. So, it's become a real problem. It's helped some people get off opioids, but it's become a real problem drug, too.

GP: It's like an over-the-counter thing?

AH: That’s right. Chris explained that it’s just like the coca leaf. It can be used to isolate cocaine, which obviously can cause problems for people, but there are many things within the coca leaf that are beneficial.

Most of the drugs that we take, unless it's a synthetic version of a hormone or a peptide, are drugs that were discovered because they have bioprospectors literally in the jungle, learning about these different plants, bringing them back, isolating the different components and seeing which ones would be good painkillers, which ones would be opioids.

So, the notion that plants and plant medicine outside of psychedelics and things like that would somehow be “woo-woo” is ridiculous. This is the origin of most modern medicines.

GP: Right. Isn't willow bark the basis for aspirin?

AH: Absolutely.

GP: And berberine is the basis for—

AH: Metformin. Berberine works as well as metformin for regulating blood sugar at a fraction of the cost.

That's something that was discovered because a biologist was studying Gila monsters. Gila monsters don't need to eat very often.

GP: What is a Gila monster?

AH: A Gila monster is one of those big, chubby, venomous Southwestern reptiles. They eat only five to 10 times per year. Some nerdy biologist was like, "I wonder how they don't get hungry." He isolated a peptide from the Gila monster. Turns out that's the GLP-1.

GP: Are you serious?

AH: Serious.

GP: I did not know that.

AH: So this is how biology—nerd biology and basic science—can lead to cures for obesity.

Even though there are some issues with GLPs.

GP: What are they?

AH: Well, you get a lot of muscle loss unless people resistance train.

GP: Can you explain why they're saying there are certain GLPs that are single agonists, double, and now there are triple agonists?

AH: The big thing that's coming out soon is retatrutide. Retatrutide is a milder agonist of GLP-1. It also increases glucagon and something called GIP. So, it hits three different pathways, each a bit more subtly. It has a lower side-effect profile, and people can lose up to a third of their body weight over a year or so.

But I do recommend avoiding black-market and gray-market sources, because you don't actually know what you're getting.

GP: I think it's been interesting to observe the whole peptide craze. You’ve got naturopaths passing around peptides and people ordering them from China. What do you think people should do to ensure safety?

AH: We're sort of where we were with supplements in the '90s, where there's really no third-party testing. If you are absolutely committed to getting true, pure retatrutide, you'll have to get it from Eli Lilly.

GP: Have you ever tried any of the peptides?

AH: Yeah, I've tried a lot of peptides. I'll experiment with things, but I rarely keep doing them for long. I tried a peptide called Pinealon, which has very little human data. I no longer take it, but I got great results from it. It gave me three hours of REM sleep a night.

GP: You're kidding.

AH: Oh, it was amazing.

GP: Is that healthy to have?

AH: That felt great to me. I thought I'd try it. I'm a bit of an adventurer. I didn't put it out there as a protocol or something to suggest to people because that's just me. That's my own use. I've taken BPC-157 if I have a joint that's in pain. I've been lucky to be pretty much injury-free. Knock on wood. But it's hard to get really true BPC-157 now, but it's out there.

GP: Why is that? Because this other company holds the patent?

AH: It's not supposed to be sold.

GP: No one's compounding it? Right. Okay.

AH: No one's compounding it.

GP: Got it.

AH: There might be some places that are. But they're not supposed to. And then I should say there are a bunch of other peptides like tesamorelin, ipamorelin, and MK-677. These are growth hormone secretagogues that people take before sleep to promote growth hormone release and sleep. Those are FDA-approved for other things and are less mysterious and cutting-edge because they were approved for other purposes by drug companies.

GP: So, what is ipamorelin approved for?

AH: For increasing growth hormone in people with reduced stature. Some people will take growth hormone to try to grow taller when they're kids. Others will take a growth hormone secretagogue. There are a couple of other clinical indications I can't quite remember. But things like melanotan, which is related to a peptide that's essentially secreted from the pituitary– it literally causes tanning of the skin. And it tends to make people hypersexual.

GP: Let me write that one down.

AH: Well, the problem is it can make people [change color]. There are some really scary images online. People have taken too much, and they turn deep bronze when their natural skin tone isn't that dark.

GP: Wow.

AH: So you might say, "Oh, that sounds great.” But it looks a bit unnatural. Some of the orange people that you see on television are probably on melanotan. It also provides immense energy, increases libido like crazy, reduces fat, and burns body fat. What's really interesting about the peptide that it mimics is that it comes from the pituitary. Not to nerd out here, but when we are in sunlight—

GP: Your favorite topic.

AH: It increases the release of this particular peptide. It's not a coincidence. Now, this peptide tans people from the inside when they take it. It's the pigmentation pathway. So, melanotan is very closely related to the dopamine pathway. Again, I don't want to start getting into the biochemistry here...

GP: We can handle it, Andrew.

AH: Well, there's an enzyme called tyrosinase, which comes from foods like hard Parmesan cheese. The crystals on the outside of Parmesan cheese are basically tyrosine. It's an amino acid that's a precursor to dopamine. Incredible, right?

GP: Amazing.

AH: The mutation that causes albinism is in the tyrosinase enzyme, which is a rate-limiting enzyme in the synthesis of melanin and dopamine.

GP: Wow.

AH: Incredible. And then you think, well, what about the beautiful arctic fox, which is white in the winter and is pigmented in the summer. Guess what? It's because sunlight activates this peptide and other pathways through tyrosinase activity, which then leads to dopamine. The animal now has energy, a heightened libido, and is pigmented. It goes out and finds mates. In the winter, it's shutdown time. Sunlight is what catalyzes these increases in dopamine and pigmentation. So a smart biochemist figured, "Oh, let's isolate this peptide." And a company said, "Oh, let's create melanotan." It's actually used to treat hyposexuality. It was first approved for women. I think the drug is called Vyleesi, something like that. I could be getting that wrong, but it’s taken in some niche communities. [Editor’s note: Vyleesi is a melanocortin receptor agonist indicated for the treatment of premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD) as characterized by low sexual desire.]

I've never taken it, but very interesting, right? Energy, libido, dopamine and mood, and activity levels for 14-hour days. You see this in the animal kingdom and in humans. I'm not recommending people take melanotan. But that's an FDA-approved peptide, for instance.

GP: Oh, is it? That's fascinating.

AH: Yeah. So, whether or not you're talking about Gila monsters in curing obesity, or you're talking about melanotan and arctic foxes turning brown and mating only during the summer—you see this in tons of different species—there's this beautiful relationship between the seasons, the sun, pigmentation, and dopamine.

GP: Right.

AH: And of course, testosterone and estrogen, which are all downstream of that. We are biological creatures, but we have this brain override that makes us try to explain everything. I think we're a lot more susceptible to things like pheromones, even though pheromone effects in humans have been hard to find. Most odors–the most primitive form of communication between animals–are instructions. People should trust their nose when picking a romantic partner. I really mean that. If their sweat smells really bad to you, if they smell bad to you, I actually think they're bad for you.

GP: Interesting.

AH: I really believe this, and there is some data supporting it. I'm convinced that when people are afraid or they're anxious, they emit certain odorants. I think we're going to start to learn more about this. It's one of the things that social media divorces us from a bit.

GP: Yeah, well, that's a whole other podcast. Speaking of which, what is the most startling thing that you've learned doing the podcast?

AH: I would say the most startling thing I’ve discovered is that we already have the biological tools to regulate our state of mind and body—to quiet the mind, or simply learn to be comfortable with its chaos. Whether you use exercise to raise your mood, long-exhale breathing to slow your heart rate, or morning sunlight to calibrate your whole system, I'm overwhelmed by how amazing the human body is if we do the right things.

GP: My husband wanted me to ask you about protein intake. He’s always lifted weights, but he says the amounts he’s seeing recommended now are insane.

AH: Some of it is insane. A teenager who’s growing very fast should follow their appetite and eat nutritious food, including plenty of protein. But this idea that everyone needs a gram of protein per pound of body weight—you start to feel like you’re being force-fed.

GP: It’s confusing. One camp says you need a lot of high-quality animal protein. Then cardiologists say avoid red meat. I’ve also read that vegetarian diets can reduce inflammation. What’s the reality?

AH: Nutrition science is messy, and a lot of the studies aren’t great. What we can say is that most people benefit from getting enough protein but not extreme amounts. For men, around 100 grams of high-quality protein per day is usually plenty. For women—depending on body size and activity level—somewhat less.

If you’re doing a lot of resistance training or trying to build muscle, you might increase that. But the idea that everyone needs enormous quantities just isn’t supported. And protein doesn’t have to come from one source. It can come from a variety of animal and plant foods.

GP: So my husband shouldn’t feel pressure to hit these huge numbers?

AH: No. If he’s maintaining muscle, feels strong, and is healthy, there’s no reason to treat protein intake like an endurance sport.