Fibre on a GLP-1 (Ozempic/Wegovy): why it matters more, not less
The gut side of GLP-1 medicines
GLP-1 receptor agonists (semaglutide, tirzepatide and others) work partly by slowing gastric emptying and gut transit. Gastrointestinal effects are commonly reported: in the STEP 1 trial, GI events (nausea, diarrhoea, constipation and others) occurred in more people on semaglutide than placebo — 74.2% vs 47.9% — with constipation among the reported effects (Wilding et al., NEJM, 2021). Persistent symptoms should be discussed with the prescribing clinician.
Eating less shouldn't mean feeding your gut less
There's a second, quieter effect: when total food intake falls, fibre intake can fall too — and your microbiome depends on that fibre for fuel. A smaller plate can mean less fibre reaching the gut, so it's worth paying attention to fibre-rich foods.
Fibre and GLP-1 point in the same direction
Fermentable fibres produce SCFAs that can influence gut-derived signals, including your body's own GLP-1 secretion; a recent review describes dietary fibre and GLP-1 therapy as mechanistically converging on appetite and metabolic control (review, ScienceDirect, 2026). This is background biology about dietary fibre — not a claim about changing how any medication works.
How to keep fibre going, gently
Aim for a small, consistent daily fibre intake rather than big irregular doses; hydrate well, since fibre needs water to help (not hinder) transit; and increase slowly, especially around dose changes when symptoms tend to flare. Some people prefer starting with small amounts of a viscous fibre such as psyllium before increasing fermentable fibres.
Always coordinate with your prescribing clinician — this is general information, not medical advice, and persistent constipation on a GLP-1 should be reviewed.
Buta-8 provides a measured daily serving of diverse dietary fibres. If you take GLP-1 medicines, ask your clinician before changing your fibre routine. See who it's for →
References: Wilding et al., NEJM 2021 (STEP 1); fibre–GLP-1 convergence review, ScienceDirect 2026.