Setup, so nobody has to ask: constipation · 1,400 kcal.
I noticed this today and I have not touched anything since, in case the state is diagnostic.
I have not discarded anything yet, so a test is still possible if that is the recommendation.
Is this recoverable, and how would I tell?
Start with what 1,400 kcal a day leaves you room for, because at that intake the deficit is a live competing explanation rather than a footnote. Protein is 4 kcal per gram, so 100 g costs 400 kcal — 29 per cent of the entire day's energy — and everything else has to come out of the remaining 1000. A day that misses protein at 1,400 kcal has missed it by a wide margin, and constipation that tracks those days is a nutrition signal. Then separate the two by timing: a dose effect is periodic and phase-locked to the injection or to an increase, and a deficit effect is monotonic and gets worse the longer the intake stays at 1,400. Log intake, protein and constipation on the same daily row for a fortnight and the two patterns separate without any further cleverness. Nothing here is medical advice.
Start with the actual intake, because a substantially suppressed appetite produces deficits far larger than intended and fatigue is the first symptom.
Sleep quality often changes during rapid weight loss in both directions, and sleep debt produces fatigue that no amount of dietary adjustment will fix.
| Event | Active arm | Placebo arm | Timing |
|---|---|---|---|
| Nausea | 40–45 % | 15–20 % | Peaks 1–2 wk after each step |
| Vomiting | 15–25 % | 5–8 % | Follows nausea |
| Diarrhoea | 20–30 % | 10–15 % | Early, variable |
| Constipation | 20–25 % | 8–12 % | Later onset, persistent |
| Discontinuation for GI events | 4–7 % | 1–2 % | Mostly during escalation |
Ranges span agents and doses; read the specific prescribing information for a specific figure.
A deficit beyond about a thousand kilocalories a day reliably produces fatigue, reduced training performance and reduced spontaneous movement. With appetite suppressed, deficits of that size arrive by accident rather than by plan.
Self-reported intake underestimates measured intake by twenty per cent or more in doubly labelled water comparisons.
Research-use compounds are not approved for human use.
Check fluid and sodium before anything more exotic.
Analytical standards and reagents with traceable certificates. Every quantitative result you read inherits the accuracy of the standard behind it.
Shop standardsThe short version: check intake, check hydration, check iron and thyroid if it persists, and only then attribute it to the compound.
Iron deficiency is common, particularly in menstruating women, and low intake plus a reduced red-meat share makes it more likely. Ferritin is the test, and it is an acute-phase reactant so it needs interpreting alongside CRP.
Fatigue that appeared abruptly, rather than gradually with the deficit, is a different pattern and points away from intake.
Ferritin as an acute-phase reactant is a recognised limitation and is why it is interpreted alongside an inflammatory marker.
The caveat is that fatigue with breathlessness, chest symptoms or sudden onset needs assessment rather than dietary adjustment.
Abrupt onset points away from the deficit and towards something else.
edited 3 Feb 2025 by v_ramaswamy — updated for the 2026 guidance change
The relevant physiology is that a large deficit reduces both available substrate and spontaneous activity, and the second is often mistaken for the first.
Three days of honest weighed intake usually settles this. Estimated intake in this situation is systematically wrong and usually wrong in the direction that hides the problem.
Concretely, carbohydrate intake specifically affects training performance and perceived energy at a given total intake, which is why very low carbohydrate approaches feel worse in the gym at matched energy.
Sleep restriction produces measurable decrements in subjective energy and in training performance independently of energy intake.
Nothing here is medical advice.
If it persists at an adequate intake, get bloods rather than more theories.
If it persists at an adequate intake, it needs blood work rather than more speculation.
Hypothyroidism, sleep apnoea, depression and anaemia all present as fatigue and all become more likely rather than less in this population, so attribution to the compound should be a diagnosis of exclusion.
Energy deficits above roughly a thousand kilocalories a day are associated with measurable reductions in resting metabolic rate, spontaneous activity and subjective energy in controlled studies.
Sleep is a variable here too, and no amount of eating fixes sleep debt.
Answering this needs to know the size of the deficit, since fatigue tracks it closely and predictably.
Dehydration from reduced fluid intake alongside reduced food intake produces headache, lethargy and postural dizziness, and is the cheapest thing on the list to correct.
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.
Weigh three days of intake honestly. That answers this most of the time.
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.