I have been interested in the use of metformin for sometime. Metformin has been shown to inhibit cell growth so for someone who is at a higher risk of cancer the benefit is obvious. On the flip side those who are looking to gain as much muscle as possible this could be seen as a negative. The ability of metformin to dispose of glucose will make it an interesting consideration for individuals who are wanting to maximize the effects of a keto diet or are carb sensitive.
Some of the effects of metformin for bodybuilders will have an impact on muscle growth... inhibition of cell growth, reduces IGF-1 receptor sensitivity, etc.
I recently added a low dose of metfromin to my cutting cycle of Test/Tren/Primo. I am currently in ketosis. I started dosing approx. 200mg (1/4 825mg tab) of metforin with two carb meals a day. My carbs were limited to 35 carbs per meal. As of yesterday I have changed the strategy. I have a 35g carb meal post am workout and no metformin. My early evening meal contains 35g carbs and 200mg metformin. Late evening meal is 50g protein only. The goal is to dispose of the glucose of the early evening meal while sleeping allowing me to immediately achieve ketosis upon waking and begin utilizing fatty acids (fat) for energy for my am training session. I have not experienced any of the gastric side effects of the drug because of the low dosage. I will up the dosage if needed based on first am ketosis urine test strip.
My personal feeling is that metformin has limited use in a pure cutting cycle. I am simply experimenting with it for personal reasons and under supervision. For those who are looking to build mass metformin should not even be a consideration . I would have to say it is useless to include it in a bulking cycle not only because of the negative impacts on cell growth but it will also reduce hunger..... not good.
Here is a short video on an explanation of metformin (glucophage). Matt is a pretty no nonsense guy.....
[[{"fid":"35266","view_mode":"default","fields":{"format":"default"},"type":"media","link_text":null,"attributes":{"alt":"In the Car with MPA: METFORMIN AND BODYBUILDING","height":165,"width":220,"class":"media-element file-default"}}]]
Here is a research paper on AMPK that Matt discusses in the video -
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2779044/
SEMPER FI