This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.
On the injection-day question: the labelling for licensed semaglutide allows the day to be changed provided at least two days separate the two injections. That interval is not arbitrary — it is what stops two doses stacking inside one absorption window.
A single observation, in a thread that deserves better than single observations.
Cardiovascular data in people without diabetes is the specific contribution of SELECT, and it is worth being precise that the enrolled population had established cardiovascular disease. That is not the same as the general population and the result should not be quoted as though it were.
I would put the burden of proof on the interesting explanation, not the dull one.
Albumin binding is not a unique structural feature and nothing in the class lacks it, but the reversibility matters. Semaglutide binds albumin covalently through a fatty side chain, which creates a very long half-life at the cost of sequestering the free form. That is a trade-off and it is the trade-off that allows weekly dosing.
That is one dataset and I would not build a rule on it.
The C-cell question: semaglutide triggered medullary thyroid carcinoma in rodent toxicology studies. A signal in rodents does not automatically appear in humans, but it is the reason the compound is contraindicated in people with personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2.
Worth reading the earlier posts in this thread before acting on mine.
Taking post #64 at face value and following it one step further.
Having read the whole SELECT thread before replying: the question in the first post has not actually been answered yet, and three of us have answered a nearby one instead.
The arithmetic in post #68 is right; the assumption feeding it is the part to check.
Is there a ceiling dose beyond which the effect plateaus? The trials did not study that because they stopped at 2.4 mg. Some people report trying higher doses, but trial data is absent and off-label dosing enters territory this site does not advise on.
Answering the question post #66 raises rather than the one it answers.
SELECT: I have looked for the primary source twice and failed twice. Either it does not exist or it is somewhere I do not know to look, and I would like to know which.
Research-use-only semaglutide is not a licensed medicine, is not manufactured to pharmaceutical standards, and is not approved for human use. That is a statement about what it is, not a coded opinion about anything.
The uncertainty is in the assumption, not in the calculation.
SELECT has a well-known answer and a correct answer, and the interesting work is establishing that they are the same. Nobody has done that here yet.
On the "does it stop working" question: tolerance in the pharmacological sense is not what the withdrawal trials show. What they show is that the effect persists while treatment continues and reverses when it stops, which is a different finding with different implications.
The 2.4 mg maintenance dose in the weight-management programme and the 1.0 mg diabetes dose are frequently discussed as though they were the same drug at different strengths. They are, but the trials behind them enrolled different populations for different endpoints, so the evidence does not transfer sideways.
Post #73 put the caveat in the right place and I want to underline it.
Injection site does not appear to matter much for semaglutide exposure. The published comparisons of abdomen, thigh and upper arm found differences small enough to be clinically unimportant, which is not true of every injectable.
This is the sort of thing the wiki should carry and currently does not.
The bit of SELECT that nobody enjoys is that the answer changes depending on what you are trying to decide with it. Say what the decision is and the thread will converge.
Semaglutide's structure is a modified backbone with a C18 diacid attached through a spacer. The acylation is the reason for the long half-life and it is also the reason a plain sequence comparison against native GLP-1 is misleading about how the molecule behaves.
Post #78 is right about the mechanism and I think understates the practical bit.
Semaglutide versus liraglutide in STEP 8: semaglutide produced greater weight reduction and the discontinuation rates differed. But the trial was open-label for the dosing schedule, which admits expectation effects. Weekly versus daily itself is part of the comparison, not a confounding variable to be removed.
The opalescent appearance in semaglutide solutions is occasionally noted and the mechanism is unclear. It does not appear to correlate with product failure in practice. Visible particles or frank cloudiness is different and would be reason to contact the supplier.
On SELECT: the maintained page in the documentation commons covers the general case with citations and a review date, which is more reliable than any reply here including this one.
On alcohol: the labelling does not contraindicate it, but it raises gastric irritation risk and semaglutide already does that. There is no published interaction study and the conservative position is to limit it if you are titrating or if gastrointestinal symptoms are troublesome.
Adding a source would improve this post and I do not have one to hand.
Injection site does not appear to matter much for semaglutide exposure. The published comparisons of abdomen, thigh and upper arm found differences small enough to be clinically unimportant, which is not true of every injectable.
Not the answer, but possibly the question that gets there.
Renal outcomes moved this compound out of the metabolic-only conversation. FLOW reported on kidney endpoints in people with type 2 diabetes and chronic kidney disease, which is a narrower population than the discussion here usually assumes.
It is worth stating the boring hypothesis before the interesting one.
Post #85 and I disagree about the size of the effect, not about the direction.
Reading back through the SELECT threads from last year, the same three questions come up every time and only one of them has ever been answered properly. That seems like a documentation gap rather than a knowledge gap.
On formulation: the licensed product is buffered and includes a preservative in the multi-dose presentation. A reconstituted research preparation matches neither, and stability claims made about the first do not carry over to the second.
It is one reading of the data and not the only reasonable one.