Claimed effect · Oxytocin (intranasal)

Does Oxytocin (intranasal) help with appetite / caloric intake?

C
Grade C — weak human evidenceSmall crossover studies · effect size: small
Short answerWeak human evidence. Small crossover studies: enough to be interesting, not enough to count on. Where an effect is seen it is a small effect. A single dose lowered food intake at a laboratory test meal in the obesity trial and in earlier crossover work — an acute effect that did not translate into weight change over eight weeks.

What the studies show

A single dose lowered food intake at a laboratory test meal in the obesity trial and in earlier crossover work — an acute effect that did not translate into weight change over eight weeks.

“Oxytocin compared with placebo was associated with reduced caloric intake at the test meal (-31.4 vs. 120.6 kcal; difference [95% confidence interval], -152.0 kcal [-302.3 to -1.7]).”

Verbatim, from the abstractPlessow F, et al. Intranasal oxytocin for obesity. NEJM Evidence, 2024;3:EVIDoa2300349

A few small or poorly-controlled human studies. Enough to be interesting; not enough to count on. Most of what gets called “clinically proven” online lives here.

  1. 1
    Plessow F, et al. Intranasal oxytocin for obesity.NEJM Evidence, 2024;3:EVIDoa230034961 adults, 8 weeks; no weight change, reduced single-meal intake.

In context

Oxytocin is a natural nine-amino-acid hormone, licensed for decades as an injection to induce labour and control bleeding. The compound sold and discussed in the peptide world is intranasal oxytocin, promoted for bonding, appetite and social behaviour. Here the evidence is largely negative: the largest randomised trial in autism found no benefit, and a randomised obesity trial found no weight loss. It is well tolerated, but the popular claims rest on small early studies that the big trials did not confirm.

Oxytocin (intranasal) is approved (rx) as injection; intranasal use unlicensed. Legal status differs by country — see the regulation section or the jurisdiction pages.

Questions

Is Oxytocin (intranasal) proven to help with appetite / caloric intake?
No. The human evidence is weak (Small crossover studies); LYO grades it C.
What studies are behind the grade?
A single dose lowered food intake at a laboratory test meal in the obesity trial and in earlier crossover work — an acute effect that did not translate into weight change over eight weeks.
Is Oxytocin (intranasal) approved for this?
Oxytocin (intranasal) is an approved medicine (Approved (Rx) as injection; intranasal use unlicensed); whether this particular outcome is a licensed indication is stated on the compound page's regulation section.

Other outcomes for Oxytocin (intranasal)

Written and maintained by LYO Research — how pages are written and checked. Reviewed 3 September 2026. Grades count human evidence only; see how LYO grades. Not medical advice. Correct this page →