AOD 9604 and NAD+ for fat loss: what the science actually says

What did @makingitglowmeredith actually say?

The creator described AOD-9604 as a peptide that tells your body to "let go" of fat, then argued it does nothing useful unless you pair it with what she called a "shuttle peptide" — a combination of NAD+ and L-carnitine — to transport released fatty acids into cells for energy production. She framed NAD+ and carnitine as the delivery mechanism that makes AOD-9604's fat-release signal actually mean something metabolically.

To be fair, she was transparent about the fact that she saw no results from AOD-9604 alone for weeks, and she disclosed this is not medical advice. She also linked to commercial sources with discount codes, which is worth flagging for context. The core claim is mechanistic: AOD releases fat, the "shuttle" burns it. That's a specific and testable idea, and it deserves a real look.

Does the science back this up?

Partially, but the framing overstates what's actually established. AOD-9604 does have some lipolytic activity in animal models, but human evidence is thin and the "shuttle peptide" concept she describes isn't a recognized clinical framework.

AOD-9604 is a synthetic fragment (hGH 176-191) of human growth hormone. Animal studies, including work by Heffernan et al. (2001, Journal of Endocrinology), showed it stimulated lipolysis in obese mice without the insulin-desensitizing effects of full hGH. That's genuinely interesting. But a Phase 2b/3 trial in humans (Metabolic Pharmaceuticals, 2007) failed to show statistically significant weight loss versus placebo. The compound never received regulatory approval for obesity. The mechanistic story in mice did not translate cleanly to humans.

On the "shuttle" side: L-carnitine does play a real role in transporting long-chain fatty acids into mitochondria for beta-oxidation (Rebouche, 2004, Journal of Nutrition). NAD+ is a genuine cofactor in energy metabolism. Neither is a "shuttle peptide" — carnitine is an amino acid derivative, NAD+ is a coenzyme. Calling them shuttle peptides is scientifically imprecise. And the idea that you need them to complete AOD-9604's mechanism assumes AOD-9604 is doing something meaningful in the first place, which in humans is not proven.

What did they get wrong (or right)?

The carnitine biology is directionally correct. Carnitine genuinely matters for fatty acid transport into mitochondria, and NAD+ is real infrastructure for energy metabolism. If you're exercising fasted and taking carnitine, there's at least a plausible rationale, even if the effect size in supplementation trials is modest. Stephens et al. (2013, Journal of Physiology) found that oral carnitine supplementation with insulin increased muscle carnitine content and reduced fat mass over 24 weeks. That's worth acknowledging.

What's wrong: calling NAD+ and carnitine "shuttle peptides" is not accurate terminology. Neither is a peptide. More importantly, the creator builds a causal story — AOD releases fat, carnitine shuttles it — that assumes AOD-9604 is producing a meaningful lipolytic signal in her body. That's a significant assumption given the human trial data. Her n-of-1 experience, where she adds two more compounds, changes her diet timing, adds fasted morning movement, and then sees results, cannot isolate AOD-9604 as the variable. The fasted cardio alone could explain the difference.

She also implies AOD-9604 "doesn't work" without the stack, which could discourage people from critically evaluating whether it works at all.

What should you actually know?

AOD-9604 is not FDA-approved for any indication. It was removed from the FDA's bulk drug substances list for compounding in 2022, meaning compounded versions are operating in a regulatory gray zone. If you're seeing it sold online or through telehealth platforms, that's a compliance issue worth asking about directly.

The "stack" approach — combining AOD-9604 with NAD+ and carnitine — has no controlled human trial evidence supporting it as a combination. Individual components have their own data profiles, and those profiles vary in quality. NAD+ precursors have more robust recent research (Yoshino et al., 2021, Science) than AOD-9604 does in humans.

If fat loss is the actual goal, the mechanisms that have consistent human evidence are caloric deficit, resistance training, adequate protein, and for eligible patients, GLP-1 receptor agonists. Peptide combinations built on animal data and n-of-1 creator experiences are not a substitute for that evidence base. Ask your provider what peer-reviewed human data supports any peptide stack before you spend money on it.