"I've tried fish oil, turmeric, and collagen-all of which helped a little
Etnyre D, Stone AL, Fong JT, Jacobs RJ, Uppada SB, Botting GM, Rajanna S, Moravec DN, Shambannagari MR, Crees Z, et al
For the full how to stack responsibly framework and when combinations actually make sense, read the pillar guide: Peptide Stacking: What Combinations Actually Make Sense (And What Doesnt)
It is used in metabolic signaling research, energy homeostasis studies, and multi-hormonal pathway investigations
On this note, a study in rats demonstrated that eight weeks of creatine supplementation increased fasting insulin levels, but studies in humans only show an increase in insulin secretion with creatine in the presence of glucose, which you wouldn't be consuming anyways during a fast (4)