I'll offer my opinion about the possible cause of your complaints, and others in this thread. I believe your fundamental assumptions about a testosterone link to libido and weight gain are absolutely incorrect. I would chalk up your weight gain, inability to lose weight, flat moods, lack of energy, disappointment about libido over time, lack of motivation, being tired, etc to time and typical age-related insulin resistance. The typical western diet has grown to include wild amounts of sugar or fined milled gains that digest instantly to sugar. Plates of pasta, masa products like tortilla chips, mashed potatoes, pizza, taco Tuesdays and margarita Fridays, not to mention sweet smoothie drinks with sugar, agave, turbinado sugar, raw sugar, honey (my point here is that it doesn't matter the form of sugar or what you call it, it's sugar), office cookies and donuts, etc, lead to decades of dousing your bloodstream with so much sugar people bloat out with insulin- over time the amount of insulin your pancreas has to release increases because your cells grow resistant, and more insulin leads to more fat storage- it's the fat-storage hormone. You can look at photos of WOMEN and men, that's right, it's not just men, decade by decade, and 90% of them start to get fuller faces, love handles, fat asses, etc. Decades later you get pre-diabetes, ED, high blood pressure, zero libidos, cranky, and stents. The typical American's bloodstream is awash with glucose. No wonder a high percentage suffer from limp dick syndrome. But I am able to lose weight on a very low carb diet, about two pounds per week if I don't cheat, and I'm taking 140mg a week of replacement T (divided M-W-F subQ). We can talk about low carb, how low carb an individual needs to be on depends on the degree of insulin resistance. Full disclosure, I am a previous fat, limp-dicked bastard guilty of all the assumptions in this thread, I'm not better than anyone else, and I am losing weight on a KETO diet. There are other diets that do the same thing (low insulin provoking diets), and those would be low-carb, Wheat Belly, South Beach, the original Atkins, and Banting. The KETO diet is just the new name for a low glycemic, low insulin hormone provoking diet. There is no new diet. All of these do the exact same thing. They cut out sugar, and things that digest as sugar (all grains). And you will lose, slowly, (as resensitizing your body once again to reasonable about of natural insulin levels takes time), and slowly lose weight. And yes, this is despite being on replacement T. The replacement T makes zero difference. Zero.