Forum lore and trial data don't always line up. Around here, the usual advice pushes the smallest dose that produces weight loss and the smallest dose that holds it off. That approach targets side effects, not benefits, and it produces a steady stream of threads asking why an obviously too-small dose isn't delivering the results someone wants.
My claim that the evidence favors keeping the original dose comes from the long-term follow-up of the semaglutide and tirzepatide trials. In those, weight stayed stable for as long as 4 years on the same dose used for loss, with no drift in either direction, right up until the trial ended and the drug stopped, at which point regain came fast even after nearly 5 years. A maintenance dose that was too high would have pushed more loss; one too low would have allowed regain. Neither happened at the loss dose. That, to me, is strong evidence from large, well-run trials that the dose which takes the weight off is the dose that keeps it off (provided loss had already stalled or plateaued, which it had in those studies).
Grey peptides come with a real drawback: no clinician in the loop. A knowledgeable endocrinologist would already understand this, even if a typical GP might not.
Specific long-term maintenance research with GLP's is still thin, and much of it tries lower doses, but I haven't seen convincing results from those efforts because of methodological problems. Better studies will arrive over the years, but for now the strongest information comes from the long-term follow-up of the original large trials.
After weight loss, particularly a large amount, energy expenditure falls: fewer cells are burning energy, and the metabolism adapts to prolonged low intake. Holding that lower weight therefore means eating less than was normal at the higher weight, and usually less than someone at that same weight who never lost anything. Hunger climbs at the same time, because the body is trying to drag you back to its abnormally high set point. Low energy needs plus extra hunger is what makes long-term maintenance almost impossible, and without GLP drugs very few pull it off.
For anyone who lost weight on GLP drugs, continuing them addresses exactly this: they blunt the excess hunger created by weight loss. With reta in particular, higher doses also raise energy expenditure by 1-200 kcal/day, and the drugs help correct many obesity-related metabolic problems such as insulin resistance, which further supports maintenance.
A second reason to stay on GLP drugs long term, particularly when obesity is or was severe, is cardiovascular prevention. Higher doses appear more effective than lower ones here. People with severe obesity are, almost by definition, already in the high-risk group for cardiovascular disease, and everyone should have blood pressure, lipids and blood sugars checked to see whether those need treatment too. Continuing the drugs prevents diabetes, heart disease, stroke, about 17 different cancers, lowers blood pressure, and improves lipids and blood sugars. This is proven for sema and tirz, not yet for reta, though given its mechanism it will likely be proven within the next few years. Past 40, and more so with age, these stop being abstract future problems: the odds of a heart attack over the next decade might reach 10-20%, so taking steps to lower that risk makes sense. Damage already done isn't truly reversible (short of bypasses or stents) and can only be kept from worsening, so prevention is clearly better. Had I acted correctly a decade ago, or had these drugs existed then, I might have avoided developing heart disease; as it stands, I can still try to keep it from progressing.
Weight loss isn't really the difficult part. Most people with obesity have shed often substantial amounts through various diets over the years, only to regain nearly all of it once they eased off the diet, myself included.
Long-term maintenance is the genuinely hard part, because it demands eating less than your body tells you to for years, and the drive to eat is deeply wired and very hard to resist over that span. I went from 145 to 75 kg mostly without glp drugs and held it for a year or so, and it wasn't my first time, but it was hard, and even with a carefully built diet to keep hunger down I was more or less permanently hungry. In all likelihood it would eventually have failed like every other attempt in my life, despite the fairly large medical risks of regaining. Fortunately I found a way to get GLP drugs without being rich, and it has made maintenance far less difficult and improved the odds of keeping the weight off long term.
