A rubbery lump of thickened fatty tissue under the skin caused by repeated injections in the same spot.
Updated Jul 18, 2026
Lipohypertrophy is a rubbery lump of thickened fatty tissue that can form under the skin when injections are given repeatedly at the same site. Injecting into one of these lumps can make medication absorption less predictable.
It is generally prevented by rotating injection sites rather than reusing the same spot.
lipohypertrophyinjectionside-effectsglossary
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