In a recent podcast discussion featuring Mike Metzger and Nathan Brooks, bodybuilders and peptide experts dissected the entire spectrum of research peptides, ranking them from most beneficial to potentially dangerous while providing context about proper usage and risk factors.
Bottom Tier: High-Risk
The discussion began with peptides that should be approached with extreme caution or avoided entirely. Dermorphin topped this list as “30 times stronger than morphine,” according to Metzger, who noted that some research sites sell this opioid receptor-hitting stuff despite having “no need to be selling something” this potent and ad**ctive.
Adipotide received similar warnings. “If you don’t inject it correctly, you could be k*lling your muscle cells,” Metzger explained. The localized cell destruction becomes particularly dangerous if it enters the bloodstream.
Metzger continued: “Heaven forbid you wind up getting that into a vein or an artery, anything that’s going to take it through your bloodstream, then it’s eliminating cells that you need instead of the fat cells.” The peptide also places considerable stress on kidney function.
DNP (2,4-Dinitrophenol) was unanimously relegated to the bottom tier. “You literally cook yourself to de*th,” Brooks stated. Metzger explained that workers in mines where DNP was present became “emaciated” from absorption through their skin, though “a lot of the mine workers were dropping d*ad from overheating.”
Modern alternatives like BAM-15 offer mitochondrial uncoupling benefits “with a way less risky profile.”
SLU-PP-332 earned scrutiny for commonly misunderstood side effects. “Some people think that it’s working better when they’re sweating more,” Metzger noted. “Oh, I’m starting to feel a little fatigued. I must be burning calories like crazy. If you’re experiencing those side effects, it means you’re not utilizing it correctly. Your body is just dumping it in the most efficient manner, which is through heat.” He emphasized that sweating and fatigue indicate excessive oxidative stress requiring immediate cessation.
Middle Tier: Effective But Situational
Melanotan-2 landed in middle tier despite its popularity. While it provides stronger tanning effects than Melanotan-1 and offers libido enhancement for both genders plus erectile dysfunction benefits for men, the risk profile raises concerns.
“If it’s going to increase the melanocytes and you have risk for skin cancer, then it’s potentially going to increase your risk for skin cancer,” Brooks explained, though he acknowledged some research disputes this connection.
Growth hormone secretagogues including Ipamorelin and CJC-1295 received lukewarm rankings. “Studies generally point to 2.6 at a maximum equivalent IU of HGH from using those,” Metzger stated. “That’s a pretty small dose. It’s okay for a longevity standpoint, but the problem is once you get past 35, the amount that you’re getting out of these things just tanks.”
Tesamorelin distinguished itself among secretagogues as “FDA approved for reducing visceral fat” with better selectivity than alternatives. However, even this superior option pales compared to direct HGH administration for those seeking significant results.
MK-677 received mixed assessment. While effective for increasing growth hormone, “your appetite is going to be increasing. People generally notice more water retention. Then you have the insulin sensitivity issues that it can create,” according to Metzger.
The insulin sensitivity impact proved particularly concerning, showing “the fastest increase in reduction of insulin sensitivity out of all” the secretagogues discussed.
NAD+ placement in second tier surprised some listeners. Despite anti-aging benefits and energy enhancement, dosing complications warranted caution.
“If your NAD+ stores are already topped up and you take a large dose of it, it can cause you to hyperventilate,” Metzger warned. “A lot of people kind of panic too if that happens.” Brooks added crucial context: “There’s a store limit to NAD that your cells can have. When you top off that store and you get a spill out of NAD, you actually get negative potential for that. There’s an inflammatory response.”
Methylene blue earned C-tier ranking due to narrow applications and interaction risks. “It will increase your serotonin, so if you’re on any anti-depressants especially or you’re utilizing another one like testofensine, you can increase your serotonin too high and you run the risk of serotonin syndrome which could be fatal,” Metzger explained from personal experience.
He continued: “I unfortunately experienced that in my own research when methylene blue was really first coming popular. I may have accidentally combined it with testofensine. You are in a state of panic, sweating, not feeling great for about 24 hours.”
Top Tier: Proven Benefits with Manageable Risks
BPC-157 achieved near-universal top-tier status, with both injectable and oral forms proving valuable. Metzger credited oral BPC-157 with managing his Crohn’s disease: “I’ve been off of all treatments for the last six years. I haven’t had to take any harsh pharmas, immune suppressing stuff or anything.”
The only significant caveat involves pre-existing conditions. “The way it heals you with increased blood flow, it can also increase the size of a tumor,” he cautioned, making cancer screening essential before use.
Brooks shared similar success with his partner’s autoimmune issues: “She was in the ER constantly. Couldn’t move, couldn’t walk, constantly in pain. The KPV has been really effective. The VIP’s been helping a lot too. In the matter of months, she’s pretty much fully recovered.”
TB-500 joined BPC-157 in top tier for injury recovery and post-surgery applications, with numerous anecdotal reports of joint and soft tissue healing. The safety profile remains excellent across various dosing protocols.
GHK-Cu (copper peptide) received top marks for multiple applications. “Whether that’s inflammation reduction, skin clearing benefits, especially if you’re talking about on the skin care research side of things,” Metzger listed.
For hair restoration specifically, “you want to look for PAL GHK-Cu. That’s the one that can actually be absorbed better through your skin or your scalp.” He credited it with maintaining his hair despite complete baldness running in his family: “Both my grandfathers were totally bald by 30 and so I still have hair 12 years older than that.”
SS-31 (Elamipretide) earned top-tier classification for mitochondrial repair. “It has shown great benefit for the mitochondrial repairing aspect,” Metzger stated. “At high doses, I’m talking 10-20 milligrams, people are recovering almost instantaneously between bursts of cardiovascular intensive exercise. Not only are you repairing your mitochondria, but you’re getting all of that performance benefit out of it too.” The peptide recently gained FDA approval for certain medical applications after the bodybuilding community demonstrated its efficacy.
MOTS-c landed in second tier below Five-Amino-1MQ despite cardiovascular benefits. “It’s great for staying leaner,” Metzger acknowledged, but raised concerns about mTOR suppression. “When you increase AMPK, you decrease mTOR. When you decrease mTOR, you’re limiting how much muscle you can put on.”
His solution involves strategic timing: “For the offseason, only utilizing those items during your off days or cardio only days. In contest prep, we had mitochondrial recovery days where we’d actually take that out and up antioxidants and also up the use of things like SS-31 that repair your mitochondria.”
Retatrutide (RETA) dominated the GLP discussion as top tier. “Something that reduces inflammation, it reduces fat. Your insulin sensitivity is better. It reduces bad cravings,” Metzger enumerated. “A lot of people that have cravings for consumption, for example, they report that being on RETA, they all of a sudden no longer crave it.”
Tirzepatide earned equal top-tier status, with personal response determining optimal choice. “Some people experience better appetite suppression on that than RETA,” Metzger noted. “It’s all personal preference. For certain use cases, especially for someone that’s just looking for fat loss, they’re not looking to compete, that glucagon addition and the increase in resting heart rate probably isn’t worth it.”
Both experts strongly cautioned against GLP use near competitions. “No one should be utilizing any of the GLPs in the last week or two weeks of a contest prep,” Metzger stated firmly. Brooks elaborated on recent experiences: “Some people having issues going into Olympia using even a dose as low as three milligrams of RETA per week” due to gastric slowing and water retention changes affecting peak week appearance.
Nootropic Peptides: Brain Health and Performance
Cerebrolysin achieved top-tier nootropic status for neuroprotection, particularly relevant given anabolic brain impacts. “I’ve written a few posts on the damage that anabolics do to the brain,” Metzger stated. “All of them at some point cause oxidative stress in the brain, cause neuron inflammation, you’re decreasing the thickness of certain points of your brain as well.”
Cerebrolysin “actually has been shown to repair the brain in traumatic brain injuries, after seizures, things like that. You’re not only reducing the oxidative stress, you’re actually repairing some of the neural connections in your brain too.”
Noopept served as the recommended entry point, offering “enhanced focus” with a “safe profile” at reasonable dosages, making it ideal for nootropic beginners.
Bromantane earned Metzger’s personal top-tier placement for dual benefits. “Not only are you going to get cognitive boost, but you’re also going to get cardiovascular improvements too. That was invented by the Russians for their special forces and their cosmonauts to not only help on the brain performance side, but also to be able to handle stressful environments.”
Dihexa received cautious evaluation despite potency. “That one’s probably the strongest out of all of them,” Metzger acknowledged. “It’s also something like 3,000 times more potent than BDNF on paper.”
Brooks raised important concerns: “People point towards BDNF as an all-inclusive benefit. But the complication is, well, there could be wrong neural networks that you’re making or inefficient neural networks. If you have bad wiring to begin with and you’re creating more bad wiring, that’s not a good thing.”
Selank achieved top-tier ranking for versatility. “With its ability to reduce anxiety while increasing your concentration, it’s really flexible,” Metzger explained. “It can be combined with a number of other maybe overstimulating nootropics to help calm it down a little bit. If you’re in a super stressful job, something like Selank can reduce that anxiety and help them get ready for bed.”
Critical Usage Guidelines
The experts emphasized that delivery mechanism significantly impacts efficacy and safety. “Certain nootropics work better intranasally. Other ones work just fine orally, some are injectable,” Metzger noted. “You have to make sure you’re utilizing the right delivery mechanism for whichever one that you’re talking about, not just whatever you see on sale.”
Cancer screening emerged as non-negotiable before starting any peptide regimen, particularly those affecting cell growth or blood flow. “The cost of blood testing has come down so much over the years. Just run the test for 40 dollars and then you know,” Metzger urged.
This proves especially critical for bodybuilders: “We’re not taking longevity doses of HGH. We’re taking longevity doses of anabolics though. That can proliferate existing cancer cells.”
Antioxidant support proved essential for mitochondrial peptides and contest preparation. Metzger shared his recovery from YK-11 inflammation: “My CRP marker got up to 20. I went off of it, went on high-dose glutathione like I was getting the IV infusions, utilized a lot of glutathione during that time. In a month, in 30 days, it went from 20 to less than one utilizing the right antioxidants.”
