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Cutting: What Actually Serves the Goal

Fat loss compounds fall into four unrelated mechanisms. Knowing which is which is the difference between a coherent plan and a shopping list.

Almost everything sold for fat loss works by one of four mechanisms, and they are not interchangeable. Incretin agonists such as semaglutide, tirzepatide and retatrutide act on appetite and gastric emptying through receptor signalling. Thermogenics such as clenbuterol act on beta-adrenergic receptors to raise energy expenditure. Thyroid hormones raise basal metabolic rate directly. Lipolytic peptides such as AOD-9604 and the mitochondrial peptides act on fat mobilisation and oxidation.

The practical consequence is that stacking two compounds from the same mechanism adds side effects faster than it adds effect, while compounds from different mechanisms behave independently. The incretin class has the strongest clinical evidence base by a wide margin, which is why it dominates the category now in a way it did not three years ago.

The category also contains compounds that preserve lean mass during a deficit rather than causing fat loss themselves. That is a different job again, and conflating the two is the most common planning error in this area.

What to weigh up

Mechanism first, not marketing

Ask which receptor or enzyme a compound acts on. Two products described identically on a label may share no mechanism at all.

Incretins need cold storage

Every GLP-1, dual and triple agonist requires refrigeration and must never be frozen. If your delivery or storage cannot support that, the compound is compromised before first use.

Beta-agonists downregulate

Continuous beta-2 stimulation reduces receptor sensitivity. This is documented pharmacology, and it is why the literature describes intermittent rather than continuous exposure.

Thyroid is not a fat burner in isolation

T3 raises metabolic rate but does not discriminate between fat and lean tissue. It is used in the literature alongside measures that protect lean mass, not on its own.