tbh i formulated brawn recompagen which has na-r-ala, berberine, bergenin and agmatine. soon after na-r-ala combined with agmatine appeared a lot. the doses are moderate but that is because of the bergenin which blocks basically any nutrient uptake into fat cells and is dosed rather high. therefore the other ingredients would have been overkill at a higher dose as people who took it 30 min. pre breakfast quite often had issues going hypo and needing to eat massive amounts of carbs to feel normal as it acts independant off insulin so it is already working with not enough glucose in the bloodstream which is why i take/took it with meals.
there is some other good ones but most are not as good for fat loss as the bergenin will induce temporary insulin resistance in fat cells. burn24 is good and berberine/banaba combinations are good which would be greatly improved by adding some high quality agmatine.
pterostilbene, pomella pomegranate and such things also work well but rather for longterm changes than immediate effects (no going hypo)
life extension ampk activator should theoretically work like metformin only a lot better as gynostemma and trans-tiliroside are a lot more potent than berberine/metformin. it also should not cause hypoglycemia but induce changes in metabolism so one can eat far more carbs and not gain fat but instead have more energy, prevent aging on a cellular level and so on. there is the old one and the new one with hesperidin, it is the old one that intrigues me the most.