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L-Cysteine Side Effects

Generic name: cysteine

Medically reviewed by Last updated on Aug 23, 2022.

Note: This document contains side effect information about cysteine. Some dosage forms listed on this page may not apply to the brand name L-Cysteine.

Applies to cysteine: intravenous solution.

Serious side effects of L-Cysteine

Along with its needed effects, cysteine (the active ingredient contained in L-Cysteine) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking cysteine:

Incidence not known

  • Anxiety
  • chest pain
  • confusion cough
  • dizziness or lightheadedness
  • drowsiness
  • fainting
  • fast heartbeat
  • feeling of warmth
  • fever
  • muscle tremors
  • nausea
  • pain, tenderness, or swelling of the foot or leg
  • rapid, deep breathing
  • redness of the face, neck, arms, and occasionally, upper chest
  • restlessness
  • stomach cramps
  • sudden shortness of breath or troubled breathing
  • unusual tiredness or weakness
  • warmth, redness, pain, or changes in skin color at the infusion site

Frequently asked questions

More about L-Cysteine (cysteine)

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.