Mercury: cellular metabolism, recalibrated

The conversation about metabolic peptides in 2025 was almost entirely about GLP-1 receptor agonists. It skipped a more interesting question: what if the real metabolic dysregulation is happening at the cellular energy level, upstream of the hormones we usually target?

The NNMT problem#

NNMT - nicotinamide N-methyltransferase - is an enzyme most people have never heard of. It does something simple and consequential: it methylates nicotinamide (a form of vitamin B3), consuming methyl groups from S-adenosyl methionine (SAM) and reducing the available pool of NAD+ precursors.

When NNMT is overexpressed - which happens in obesity, type 2 diabetes, and aging - three things go wrong. NAD+ availability declines, impairing mitochondrial function and sirtuin signaling. SAM gets depleted, affecting countless methylation-dependent processes. And methylated nicotinamide accumulates, with consequences we are still mapping.

Research from the Brenner lab and others has shown that NNMT expression in adipose tissue correlates with metabolic dysfunction more reliably than most conventional markers.

5-Amino-1MQ: the NNMT inhibitor#

5-Amino-1MQ is a small molecule (technically not a peptide, but it travels in peptide circles) that selectively inhibits NNMT. In preclinical models, it restores NAD+ pools, improves mitochondrial function, and produces metabolic improvements that look qualitatively different from caloric restriction or GLP-1 effects.

The most cited study showed that 5-Amino-1MQ administration in diet-induced obese mice produced significant fat loss, improved insulin sensitivity, and increased adipocyte mitochondrial biogenesis - without affecting food intake.

That last detail is important. Most weight-loss interventions work by reducing intake. This one appears to work by changing how the body uses energy.

AOD-9604: the engineered GH fragment#

AOD-9604 is the C-terminal fragment of human growth hormone - specifically, amino acids 176-191. It was developed in the late 1990s by Metabolic Pharmaceuticals, with the explicit goal of isolating GH's lipolytic effects from its growth-promoting and glucose-disrupting effects.

The mechanism: AOD-9604 stimulates lipolysis and inhibits lipogenesis in adipose tissue, but it does not activate the GH receptor in a way that triggers IGF-1 release or affects blood glucose. In other words: fat-loss signaling without the somatic and metabolic side effects of full-length GH.

AOD-9604 was taken into human obesity trials in the 2000s by Metabolic Pharmaceuticals, but those trials were never published in the peer-reviewed literature and did not establish a clear efficacy signal. The lipolytic effect is best supported by preclinical work in animal models.

Why combine them#

5-Amino-1MQ works at the cellular energy level - restoring NAD+, improving mitochondrial function, increasing the body's metabolic rate from the inside out. AOD-9604 works at the tissue level - directly signaling adipose tissue to oxidize fat. The combination addresses metabolic dysregulation at two different layers of the system.

This is the opposite of how GLP-1 receptor agonists work. GLP-1s primarily reduce intake through appetite suppression and slowed gastric emptying. Mercury does not suppress hunger - it shifts how the body processes energy.

Important caveats#

• 5-Amino-1MQ research is overwhelmingly preclinical. Human data is limited.
• AOD-9604 human trial data is limited and was not published in peer-reviewed journals. Its lipolytic effect is demonstrated preclinically, not in controlled human studies.
• This stack is not a GLP-1 replacement. It is a different angle on the same problem.
• Stacked with caloric restriction or training, the effects compound.