Peptide library / Skin & aging / Difelikefalin
Difelikefalin
A kappa opioid receptor agonist peptide that relieves itch in people on dialysis.
Effects studied or claimed
What it is used or promoted for, and where each effect has actually been seen
- Itch in chronic kidney disease on hemodialysisFDA approved
How it is thought to work
Difelikefalin acts on kappa opioid receptors outside the brain, which dampens itch signals without the central effects of typical opioids.
What the evidence shows
The KALM trials showed less itch than placebo over 12 weeks.
Safety and unknowns
Diarrhea, dizziness and nausea are the most common effects.
Regulatory status
FDA-approved as Korsuva in 2021 as an injection given at dialysis.
Regulatory status changes quickly. This entry was last reviewed on 27 October 2026. Confirm current status with the FDA before relying on it.
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General information, not medical advice. Do not buy or inject unregulated peptides.