Decent study on metabolic rate, t3 increases from Supplements with phosphate. Best used and most effective for fat loss when on a cutting diet. Reserves energy from carbohydrates while adding more fat burning potential.

Cytomel, t3, t4, cutting down after a bulk cycle


Adding a mineral supplement containg Phosphate to your diet while cutting,especially with a low carb diet,will help keep your natural T3 levels higher,that makes your dieting more effective by keeping your metabolic rate high even while on a low energy diet. Phosphate by keeping T3 from downregulating will give you more fat burning potential and more energy for workouts during low carb cuts. I don't see a big downside here and it's something that could even help after a T3 ramp. Here's some backround on the subject. I haven't tried it yet but plan to when I cut again.


Phosphate supplementation prevents a decrease of triiodothyronine and increases resting metabolic rate during low energy diet.

Thirty overweight women participated in 8 week slimming program consisting of a self-controlled low-energy diet (4.2 MJ/day) supplemented with highly viscous fibres and mineral tablets containing calcium, potassium and sodium phosphates (Redusan Combi, Biokraft Pharma AB, Sweden). Half of the patients received in double blind manner mineral tablets during first 4 weeks and placebo (without phosphates) during next 4 weeks (group 1) while the remaining patients were treated (cross-over) with placebo first and mineral tablets in the final period (group 2). The rate of weight loss was similar in groups 1 and 2 (4.7 vs 5.2 kg during the first 4 weeks and 2.7 vs 3.0 kg in the further 4 weeks). During periods of phosphate supplementation, the resting metabolic rate (RMR) increased by approx. 12% (p < 0.05) in group 1 and 19% (p < 0.05) in group 2. Phosphate supplementation ameliorated also a decrease in plasma triiodothyronine level and a decrease in thyroxine to triiodothyronine ratio. There were no differences between groups in the plasma insulin, catecholamine, growth hormone, cortisol and testosterone levels. Phosphate supplementation did not affect plasma lipids or blood glucose concentration. It is concluded that phosphate supplementation in obese patients on a low-energy diet enhances RMR irrespectively of the rate of weight loss. This effect seems to be, at least partly, due to an influence of phosphates on peripheral metabolism of thyroid hormones

J Physiol Pharmacol 1996 Jun;47(2):373-83 (ISSN: 0867-5910)
Nazar K; Kaciuba-Uscilko H; Szczepanik J; Zemba AW; Kruk B; Chwalbinska-Moneta J; Titow-Stupnicka E; Bicz B; Krotkiewski M
Department of Applied Physiology, Polish Academy of Sciences, Warsaw, Poland.