Research

Hormonal

In obese individuals, chronically elevated leptin levels induce leptin resistance through impaired blood-brain barrier transport and central receptor signaling deficits, rendering exogenous leptin therapy ineffective for weight loss.

If you are obese, your body likely already has high levels of leptin, but your brain has stopped listening to it (leptin resistance). Therefore, taking leptin supplements or injections will not help you lose weight. The focus should be on improving metabolic sensitivity rather than adding more hormone.

GoodRefutesHIGH confidence
Chronically raised leptin levels which characterize obesity decrease the transport of leptin into the CNS and impair the signaling properties of leptin receptors. The resulting resistance to leptin confers increased susceptibility to diet-induced obesity, which in turn raises leptin levels further and worsens existing leptin resistance leading to a vicious cycle of weight gain.
Ashwini Oswal et al. · Obesity · 2009

Why this rating

The paper is a comprehensive review citing multiple human and rodent studies, though it acknowledges unresolved questions in humans.

Source

Leptin and the Control of Body Weight: A Review of Its Diverse Central Targets, Signaling Mechanisms, and Role in the Pathogenesis of Obesity

Ashwini Oswal et al. · Obesity · 2009

DOI 10.1038/oby.2009.228

narrative_reviewCited 166×
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DOI resolved against Crossref · corpus check 2026-06-10

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