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Every product on our Independent Analysis page has one or more Certificates of Analysis (CoAs) from MZ Biolabs, an independent analytical laboratory in Tucson, Arizona. We publish them so you don't have to take our word for what's in the vial or tablet.

A CoA is only useful if you know how to read it. This guide goes through one of our reports section by section, explains what each number means and shows you how to check that a CoA, ours or anyone else's, is genuine.

We'll use our Ostarine (MK-2866) report, analysed March 2023, as the worked example. Open it alongside this post and follow along.

All information is for educational and research purposes only.

MK-677 has appeared in our SARM Showdowns twice already, against RAD-140 and against Cardarine. Each time we pointed out that it isn't actually a SARM. It is a growth hormone secretagogue: a compound that prompts the body to release more of its own growth hormone (GH).

It isn't the only one. Two peptides, Ipamorelin and CJC-1295, act on the same system but in different ways. This three-way Showdown compares the oral option against the two peptide options.

All information is for educational and research purposes only.

First, How Growth Hormone Release Works

The pituitary gland releases growth hormone in pulses, mostly during deep sleep. Three signals control it:

• GHRH (growth hormone-releasing hormone) from the hypothalamus tells the pituitary to release GH.
• Ghrelin, the "hunger hormone", acts on a separate receptor (GHS-R1a)

Mitochondria, the parts of the cell that produce energy, are one of the busiest areas of performance and longevity research. Two names now come up in almost every discussion: MOTS-c and NAD+.

Both are linked to cellular energy, metabolism and age-related decline, and they are often mentioned together. But one is a peptide made by the mitochondria and the other is a coenzyme the mitochondria depend on. This Showdown explains how they differ and why they are more complementary than competing.

All information is for educational and research purposes only.

MOTS-c — The Mitochondria's Own Messenger

What it is: MOTS-c is a 16-amino-acid peptide. Unusually, it is encoded by mitochondrial DNA, not the DNA in the cell nucleus. It was discovered in 2015 and belongs to a newly recognised class called mitochondrial-derived peptides.

How it works:

Our SARM Showdown series has become some of the most-read content on the Peak Body blog, so we're bringing the same head-to-head format to peptides. What better place to start than the two names that come up in every recovery discussion: BPC-157 and TB-500?

They are often mentioned together, and sometimes as if they were interchangeable. In fact they come from very different sources, are thought to work in different ways and have different kinds of research behind them.

All information is for educational and research purposes only.

BPC-157 — The Gut-Derived Healing Peptide

What it is: BPC-157 ("Body Protection Compound") is a 15-amino-acid peptide. Its sequence is taken from a protein found naturally in human gastric juice.

Research background: most BPC-157 research comes from one research group at the University of Zagreb, which has published a large number of animal

Across our SARM Showdown series, one question keeps coming up: what actually makes a SARM different from a steroid? On forums and social media the terms are often used as if they mean the same thing. They don't.

This guide explains the three categories: what they are made of, how they act on the body and why "selective" is the key word. It also covers several popular compounds that are usually called SARMs but aren't.

All information is for educational and research purposes only.

The Common Thread: the Androgen Receptor

All three categories involve the androgen receptor (AR). This is a protein inside cells that, when activated, switches on genes involved in muscle growth, bone density, red blood cell production and male sexual characteristics.

The androgen receptor is found throughout the body, including muscle, bone, prostate, skin, hair follicles, liver and brain. That spread is the key to the whole comparison.

We've compared both of these compounds with RAD-140 before, but never with each other. That's a notable gap, because Ostarine (MK-2866) and LGD-4033 (Ligandrol) are probably the two most talked-about SARMs, and they are also the two with the most human research data.

Both are non-steroidal selective androgen receptor modulators. Both have been through human trials. Both come up regularly in lean-mass research. They differ mainly in potency, how far development went, and the kinds of research questions each is usually linked to.

All information is for educational and research purposes only.

Ostarine (MK-2866) — The Most Clinically Studied SARM

Ostarine, also called enobosarm or GTx-024, was developed by GTx Inc. It binds to the androgen receptor with high selectivity for muscle and bone. It was designed to have much less effect on tissues such as the prostate and skin.

Few SARMs have been through as

Our last Showdown covered the strength compounds: S-23, YK-11 and RAD-140. This one covers the other end of the spectrum. When the research focus is fat loss, body recomposition or endurance, three compounds come up more than any others: Ostarine (MK-2866), Cardarine (GW-501516) and Stenabolic (SR9009).

Only one of them is actually a SARM. Cardarine and Stenabolic are often grouped with SARMs, but they act on completely different targets in the body. That difference is the main point of this comparison. We look at what each compound is, how it works and what the published research says. Then we compare them side by side for cutting-focused research.

All information is for educational and research purposes only.

Ostarine (MK-2866) — The Lean Tissue Preserver

Ostarine, also known as enobosarm, is a non-steroidal selective androgen receptor modulator. It was originally developed by GTx Inc.