|
PUBLISHED BY NLL LABS
The Protocol
Peptide science, news, and stacks. Every Tuesday. No fluff.
ISSUE 001 · MAY 26, 2026 · 5 MIN READ
A peptide just hit 28.7% weight loss.
That's the highest number ever published.
It's also not FDA approved, the supply is full of fakes, and the people running it are doing one specific thing right. Read on.
|
|
| |
|
IN THIS ISSUE
5 things, 5 minutes.
|
01 · TRIAL
Retatrutide just hit 28.7% body weight loss in TRIUMPH-4 Phase 3. Highest GLP-1 number ever published.
|
|
02 · RESEARCH
BPC-157 decoded: the "healing peptide" people use for tendons, gut, and recovery. Plus 3 new studies linked.
|
|
03 · STACK
The "lose fat, keep muscle" protocol the community is running right now.
|
|
04 · ALERT
Sub-90% Retatrutide is in the supply chain right now. How to spot it.
|
|
05 · DEEP CUT
How lizard venom built the $50 billion GLP-1 industry.
|
|
|
| |
|
01 · THE OPENER
Welcome to Issue 001. The peptide world is moving faster than the FDA can keep up, and most of what's published is either drug-company press releases or forum guesses. The Protocol exists to give you the truth. Backed by science and studies. Not trying to sell you a product.
No vendor pitches. No magic-bullet claims. Every claim sourced. Five minutes. Then back to your day.
|
|
| |
|
02 · THIS WEEK IN PEPTIDES
Retatrutide just lapped the entire field.
Eli Lilly dropped the TRIUMPH-4 Phase 3 readout in April. Headline number: 28.7% body weight loss at 12 mg over 68 weeks in adults with obesity plus knee osteoarthritis. For context: that's roughly 10 percentage points higher than Semaglutide (Ozempic) and 5 higher than Tirzepatide (Mounjaro/Zepbound).
| 1. |
It's a triple agonist. GLP-1 + GIP + Glucagon. Sema hits one receptor, Tirz hits two, Reta hits all three. That's the entire reason for the lap. |
| 2. |
The heart numbers are real. At top dose: systolic blood pressure down 14 mmHg. Triglycerides, non-HDL, hsCRP all moved the right way. This isn't just weight loss, it's cardiometabolic. |
| 3. |
Not FDA approved yet. Earliest NDA filing is Q4 2026. TRIUMPH-1 (the anchor trial for approval) reads out Q2 to Q3 this year. |
|
WHY IT MATTERS
If you've ever plateaued on Sema or Tirz, Reta is the answer the trials suggest. But the compound isn't FDA-approved yet, which means the supply is the Wild West right now. More on that in Vendor Watch below.
|
Sources: NEJM Phase 2 (Jastreboff et al., 2023) · Eli Lilly Q1 2026 investor release · TRIUMPH-1 (NCT05882045).
|
|
| |
|
"Sema hits one receptor. Tirz hits two. Reta hits all three."
Mechanism summary · Jastreboff et al., NEJM 2023
|
| |
|
03 · PEPTIDE OF THE WEEK
BPC-157, decoded in 90 seconds.
The "healing peptide" people use for everything from torn rotator cuffs to leaky gut. Discovered in 1991. Still no FDA approval, still wildly popular. Here's why.
| CLASS |
Synthetic pentadecapeptide (15 amino acids). Derived from a protective sequence found in human gastric juice. |
| MECHANISM |
Angiogenic. Promotes new blood vessel formation at injury sites, accelerating tissue repair. Modulates nitric oxide and upregulates growth factors (VEGF, FGF). Particularly active in gut tissue, tendon, and ligament. |
| HALF-LIFE |
~30 minutes injected, but tissue-level effects last much longer. Daily or twice-daily injection typical. Oral capsules now also available (gut-specific use cases). |
| WHO IT'S FOR |
Tendon, ligament, joint injuries. Gut issues (IBD, ulcers, leaky gut). Post-surgical recovery. Slow-healing wounds. Athletes managing chronic wear. |
| REPORTED EFFECTS |
Gut symptom relief within days to weeks. Tendon healing accelerates over 4 to 8 weeks (vs. 8 to 16 weeks untreated in animal models). Systemic anti-inflammatory effect. Often stacked with TB-500 for synergy (Sikiric et al.). |
| WATCH FOR |
Generally well-tolerated, no major adverse events in published animal data. Human RCTs are limited. Theoretical concern: the same angiogenic mechanism that heals tissue could theoretically feed tumors. Not recommended for active cancer patients. |
|
Want a specific peptide decoded in a future issue? Hit reply anytime with the name. We log every request. Most-requested compounds get covered first. First-name credit when we run yours. (For next week's pick, vote at the bottom.)
|
|
|
| |
|
04 · IN THE LAB
3 studies you missed.
| TESAMORELIN |
Visceral fat data keeps holding up. Long-term users in HIV-lipodystrophy trials show sustained VAT reduction at 26 and 52 weeks, no loss of glycemic control.
What this means: Tesa works in chronic use without metabolic punishment. Off-label use in healthy adults is still under-studied. Read on PubMed →
|
| BPC-157 |
Oral bioavailability paper from Sikiric's lab. The acid-resistant sequence survives gastric passage in animal models at clinically relevant concentrations.
What this means: Oral BPC-157 isn't placebo, but injection still wins for systemic effects. Capsules are a real option for gut-specific issues. Read on PubMed →
|
| GHK-CU |
Microneedling synergy confirmed. Topical GHK-Cu applied immediately after a microneedling session shows ~3x penetration vs. baseline cream application.
What this means: Same compound, different delivery, dramatic effect difference. If you're already paying for GHK-Cu, the application protocol decides the ROI. Read on PubMed →
|
|
|
| |
|
05 · STACK SPOTLIGHT
The "lose fat, keep muscle" cycle.
Posted by a community member running this for 12 weeks. Anonymized, real numbers.
| GOAL |
Aggressive fat loss without losing the muscle that took years to build. |
| STACK |
Retatrutide + CJC-1295/Ipamorelin + MOTS-c. |
| LOGIC |
Reta kills appetite + burns fat. CJC/Ipa amplifies the natural GH pulse overnight to protect lean mass. MOTS-c activates AMPK (the exercise pathway) for energy through the deficit. |
| WEEK 12 |
Significant fat loss with lean mass retention measurable on DEXA. The cut people post photos of. |
Specific dosing varies by body, goal, and individual response. Not medical advice. Don't run blind. Talk to someone who knows what they're doing before starting.
|
|
| |
|
06 · VENDOR WATCH
The Retatrutide purity problem.
Reta is hard to synthesize. The demand spike pulled in vendors cutting corners. Independent third-party labs (Janoshik, Finrick Analytics, Simec) have caught "research Retatrutide" batches testing under 90% purity in the past quarter. Some under 80.
At under 90% purity, you're not getting the drug. You're getting whatever side-products the manufacturer didn't filter out, plus 80% of the dose you paid for. That's not "research grade." That's contaminated.
DEMAND THIS BEFORE YOU BUY:
| ▸ |
HPLC and LC-MS COA. HPLC alone misses contamination at the molecular level. |
| ▸ |
Batch-specific COA. Tied to the lot number on your vial, not a generic vendor cert. |
| ▸ |
Independent lab on the cert. Vendor-internal labs don't count. |
| ▸ |
99%+ purity floor. Under that is a discard, not a discount. |
|
If a vendor won't show you the COA before checkout, that's the answer. Walk away.
|
|
|
| |
|
"Every GLP-1 drug on the market today traces back to a 1992 paper on lizard venom."
Historical synthesis · Eng et al., J Biol Chem 1992
|
| |
|
07 · DEEP CUT
The Gila monster fueled a $50 billion industry.
In 1992, John Eng, a researcher at the Bronx VA Medical Center, was studying the venom of Heloderma suspectum, the Gila monster. The lizard, native to the Sonoran Desert, has a strange habit: it eats 3 to 4 times per year and metabolizes those meals for months. No human could survive that. The Gila monster thrives.
Eng isolated a peptide from the venom that mimicked human GLP-1 but was radically more stable. Native GLP-1 breaks down in your bloodstream within 2 minutes. The lizard version, which he named Exendin-4, lasted hours. He published the discovery in the Journal of Biological Chemistry in 1992.
Thirteen years later, in 2005, the FDA approved Exenatide (Byetta), the synthetic copy of Exendin-4. It was the first GLP-1 drug ever sold. Every drug that followed, Liraglutide, Semaglutide, Tirzepatide, Retatrutide, owes its existence to that lizard.
Today the GLP-1 market is north of $50 billion annually. Every dose in every patient's fridge is a descendant of a peptide we extracted from venom. That's how breakthrough drugs actually get discovered: someone looking at something nobody else would look at.
|
|
| |
|
08 · READER Q
"Can I mix two peptides in the same syringe?"
Short answer: usually yes for water-based peptides, with rules.
What's safe: peptides reconstituted in bacteriostatic water with compatible pH ranges. The classic example is CJC-1295 + Ipamorelin, which many vendors sell pre-blended. Drawing both into one syringe at injection time is functionally identical.
What's risky: mixing across solvents (ethanol-based with water-based), incompatible buffer chemistries, or peptides at extreme pH differences. Worst case you get precipitation. A cloudy syringe means your peptide just denatured into garbage. You paid for it. Don't waste it.
Rule of thumb: if your vendor sells them as a pre-mixed blend, you can combine them. If they don't, keep separate vials. The two seconds of "convenience" isn't worth a dead $200 vial.
Got a question? Hit reply. First-name credit when we feature it.
|
|
| |
|
09 · THE LONG GAME
The free peptide.
Before any compound can do its job, your circadian rhythm has to be locked in. Ten minutes of direct sunlight in your eyes within an hour of waking does more for hormonal optimization, sleep quality, and dopamine production than any peptide on the market. Cortisol pulse aligns. Melatonin schedules itself for 14 hours later. Free, daily, non-negotiable. Run this before you spend a dollar on anything else.
|
|
| |
|
10 · NEXT WEEK · YOU VOTE
Pick next week's Peptide of the Week.
Three candidates on the table. Most votes by Friday at midnight ET wins next Tuesday's slot. Hit reply with A, B, or C.
| A |
Tesamorelin
The visceral fat peptide. Why timing destroys it, and the GH pairing nobody talks about.
|
|
| B |
CJC-1295 with DAC
The long-acting GH peptide that everybody runs alongside Ipamorelin. Most stack it wrong.
|
|
| C |
Kisspeptin-10
The peptide that elevates natural testosterone. LH pulse, no exogenous hormones, no shutdown.
|
|
Reply with your pick. One letter is fine. Or write in your own peptide if none of these are it (Wolverine, GHK-Cu, MOTS-c, Sermorelin, anything). The most-requested compound ships Tuesday.
|
|
| |
|
P.S. The one thing nobody tells you before you start.
Before you run your first peptide cycle, pull a baseline blood panel. CBC, comprehensive metabolic, lipids, hsCRP, fasting insulin, IGF-1, free + total testosterone, estradiol, thyroid (TSH, free T3, free T4).
Doable through Quest direct-pay, biohacker clinics, or your primary care if you ask the right way. Costs less than one vial of Reta. Re-run every 8 to 12 weeks during a cycle.
Without baseline numbers, you cannot tell what worked, what hurt, or what your normal is. Three months in, when you feel different, you'll have no idea if it's the GH pulse, the metabolic shift, the inflammation drop, or random life noise. Take the panel. Save the PDF. Then start the stack. The people who get the most out of peptides do this. The people who get burned skip it.
|
|
| |
|
|
|
THE PROTOCOL · PUBLISHED BY NLL LABS
Missed an issue? Read past issues · Not your thing? One-click unsubscribe
The Protocol is an educational publication. Nothing here is medical advice, prescription, or solicitation to purchase. Compounds discussed are for in vitro research use only. Must be 21+ to subscribe.
NLL Labs · New York, NY
nextlevel-labs.com
·
@readtheprotocol
·
unsubscribe
|
|