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How do I tell constipation from an energy deficit on 900 kcal a day?

Asked 5 Mar 2025Modified 15 months agoViewed 21k times
25

Conditions: constipation · 900 kcal.

I think I have a problem. I am not yet sure whether it is a real problem or a measurement artefact.

I want to know whether this is recoverable or whether the honest answer is to write it off.

Should I be treating this as a failure or as noise?

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YM
askedyuki_morishita19k185 Mar 2025

5 Answers

Accepted answer first, then by votes
76

Accepted answer

More usefully, the mechanism explains the pattern. Delayed gastric emptying plus central appetite suppression produces early satiety, and early satiety plus a slowed transit produces exactly the symptom cluster people report.

Constipation outlasts the nausea because it has two causes and only one of them resolves. Gastric emptying accommodates over weeks; total intake, and therefore stool volume and the osmotic load reaching the colon, does not recover until intake does. This is why fibre alone can make it worse — you add bulk to a system that is short of water and short of motility.

Gastrointestinal adverse events, indicative pooled rates

EventActive armPlacebo armTiming
Nausea40–45 %15–20 %Peaks 1–2 wk after each step
Vomiting15–25 %5–8 %Follows nausea
Diarrhoea20–30 %10–15 %Early, variable
Constipation20–25 %8–12 %Later onset, persistent
Discontinuation for GI events4–7 %1–2 %Mostly during escalation

Ranges span agents and doses; read the specific prescribing information for a specific figure.

The telogen effluvium timing signature is the diagnostic feature: hair enters the shedding phase two to four months after the insult, so shedding that starts at month three of rapid loss and peaks around month four to five is the expected pattern. Shedding that starts in week two is not telogen effluvium and warrants a different question. In either case the follicle is not destroyed and regrowth is the rule.

The prescribing information for each agent lists adverse reaction frequencies against placebo in a table, and reading that table is more informative than reading a hundred anecdotes, because it has a denominator.

Most of this resolves. The point of knowing the pattern is to recognise the small fraction that does not.

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CF
answered · acceptedclaudia_ferrante46k3810 Apr 2025
6Does this hold at lower concentrations, or does adsorption dominate? – vialroom 4 months ago
5Worth flagging that this changed in 2025, so older answers on the site are out of date. – tabular_nums 2 months ago
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59

Concretely, the honest framing is that this is very common, usually self-limiting, and occasionally the presentation of something that is not self-limiting at all — and the differentiating features are specific enough to be worth knowing.

Distinguishing an injection-site nodule from an infection: a nodule is firm, non-tender or mildly tender, not warm, not expanding, and appears within a day or two. Cellulitis is warm, tender, expanding, and often accompanied by systemic features. A sterile abscess sits between the two and is fluctuant. Warmth plus expansion plus fever is the combination that stops being a forum question.

Stated carefully, fatigue attribution is a subtraction problem. Take out the energy deficit, the dehydration, the electrolyte shortfall and the poor sleep, and what remains attributable to the drug in the trials was modest — placebo-arm fatigue rates were within a few points of active-arm rates in most of the programme. The corollary is that the fixable causes are usually the actual causes.

Write down in advance which symptoms mean stop and seek care. It is a short list and it is much easier to write when you are well.

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LS
answeredlukas_sedlacek17k2714 May 2025
35

The relevant detail is that the distinction worth making early is between a tolerability problem, which is unpleasant and self-limiting, and a clinical problem, which is neither. They present differently and the thresholds for each are worth writing down before you need them.

Pancreatitis red flags worth memorising rather than looking up: severe, persistent epigastric pain radiating to the back, worse lying flat and better sitting forward, with nausea and vomiting that does not settle. That combination is an urgent assessment, not a dose adjustment. An isolated lipase elevation without that picture is common and usually not pancreatitis.

Vomiting matters mostly through its consequences. Loss of gastric fluid depletes sodium, chloride and potassium, and hypokalaemia presents as exactly the fatigue and cramping people attribute to the drug. Persistent vomiting also makes a renal panel uninterpretable, because a pre-renal picture looks like renal impairment.

Telogen effluvium following substantial weight loss is documented independently of any pharmacotherapy, which is the cleanest argument that the rate of loss rather than the agent is the primary driver.

Worth being explicit: nothing here is medical advice, and research-use-only compounds are not approved for human use.

Fix the fixable causes first — fluid, electrolytes, sleep, intake — before concluding that the compound is responsible.

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LC
answeredlyoph_cake95k25821 Apr 2025
3

Timing is the most useful diagnostic feature here and it is the one most often omitted from the question.

The gallbladder signal tracks the rate of weight loss more than it tracks the drug. Rapid mobilisation of adipose tissue increases biliary cholesterol saturation and reduces gallbladder motility; that combination is lithogenic whether the loss came from a drug, a very-low-energy diet or bariatric surgery. The drug contribution on top of that is present but smaller than the rate contribution.

The pooled gastrointestinal adverse-event rates across the STEP programme and the SURMOUNT programme are reported in the primary publications and in the FDA and EMA assessment reports, and the assessment reports are more useful because they give the placebo-arm rates alongside the active-arm rates in the same table.

If the timing does not fit the escalation, look for another explanation before settling on the drug.

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AD
answeredanouk_desmet18k2819 Mar 2025
3Does this hold at lower concentrations, or does adsorption dominate? – rosa_mendieta 8 months ago
4Worth flagging that this changed in 2025, so older answers on the site are out of date. – bufferline42 10 months ago
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2

Look at the placebo arm before concluding anything about attribution. The placebo-arm rates for most of these events are not small, because the events themselves are common in the underlying population.

Injection-site reactions are more often diluent-related than peptide-related. Benzyl alcohol sensitivity is uncommon but real, and it presents as a consistent local reaction at every site with a preserved diluent and no reaction with an unpreserved one — which is a straightforward thing to establish. Injection depth is the other common cause: intradermal placement stings and welts, subcutaneous placement usually does not.

I would flag that attributing a symptom to a drug is a hypothesis, and the base rate of these symptoms in the general population is high enough that the hypothesis is often wrong.

A symptom diary with dates against dose steps answers most of these questions without anyone needing to guess.

edited 12 May 2025 by plate_count_9k — added a caveat about sampling

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P9
answeredplate_count_9k95k1582 May 2025

Your answer

Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.

Not medical advice. Research-use-only compounds are not approved for human use.