Medication · Inflammation & immunity
Corticosteroids (prednisone, dexamethasone)
Often nudges weight up
Famous for appetite, fluid and a change in face and trunk shape.
The reasons room
When it isn't food or movement at all
A great many weight changes are caused by a prescription or a diagnosis. Look yours up here and you'll usually find a mechanism — a real, physical reason — instead of a character verdict.
Medication · Mood & mind
Antidepressants (SSRIs, mirtazapine, tricyclics)
Can go either way
Very drug-dependent — some raise appetite, some flatten it, some do neither.
Medication · Mood & mind
Antipsychotics (olanzapine, quetiapine, risperidone)
Often nudges weight up
Among the strongest medication effects on weight there is.
Medication · Blood sugar
Insulin & sulfonylureas
Often nudges weight up
Weight often rises because the body finally starts keeping its fuel.
Medication · Blood sugar
GLP-1 medicines (semaglutide, tirzepatide, liraglutide)
Often nudges weight down
Slow the stomach and quieten 'food noise'.
Medication · Heart & blood pressure
Beta-blockers (propranolol, atenolol)
Often nudges weight up
A small gain, mostly from doing less and burning slightly less.
Medication · Hormones
Hormonal contraception
Mostly fluid, not fat
Mostly fluid and breast tissue; the depot injection is the main exception.
Condition · Hormones
Hypothyroidism
Often nudges weight up
The whole body idles slower — and holds a puffy kind of weight.
Condition · Hormones
PCOS
Often nudges weight up
Insulin resistance makes storing easy and releasing hard.
Condition · Hormones
Cushing's syndrome
Often nudges weight up
The body's own cortisol runs high — rare, but very treatable once found.
Condition · Heart & kidneys
Heart failure & kidney disease
Mostly fluid, not fat
Rapid weight gain here is fluid, and it is a warning sign.
Condition · Hormones
Hyperthyroidism
Often nudges weight down
Everything speeds up — often with weight loss despite eating more.
Condition · Digestion
Coeliac disease & IBD
Often nudges weight down
The gut stops absorbing what you eat.
Condition · Whole body
Cancer, long COVID & chronic illness
Can go either way
Illness rewrites appetite, energy and muscle in both directions.
Condition · Whole body
Lipoedema & lymphoedema
Mostly fluid, not fat
Tissue that doesn't respond to diet at all — because it isn't ordinary fat.
Condition · Whole body
Sleep apnoea
Often nudges weight up
A two-way street: it's worsened by weight and it also causes weight gain.
This room explains patterns, not your prescription. Never change or stop a medicine because of something you read here — bring it to the person who prescribed it. Often there's a sibling drug that suits your body better.