Lysine is likely safe when used at recommended doses (<3000mg/day) for up to 6 months. If you are unsure about the dose you are currently taking, please consult with your health care practitioner. Side effects may include cramping, stomach pain, and diarrhea. Rarely, it can cause gallstones, kidney and liver damage.
Lysine may increase absorption of calcium and decrease the loss of calcium in urine. To avoid calcium toxicity, check with your health care provider before using lysine if you are taking calcium supplements.
Lysine may increase the risk of bleeding and therefore should be used with caution by people with bleeding disorders. It may interact with medications that can increase this risk, such as anticoagulant medications (e.g., warfarin, heparin) and anti-platelet medications (e.g., clopidogrel).
Lysine may increase the risk of low blood sugar if you take medication for diabetes.
Speak to your health care provider before using lysine if you have:
- bleeding disorders
- high cholesterol levels
- a modified diet (e.g., low protein)
- pancreas problems
- thymus disorders
- a weakened immune system
Use of lysine during pregnancy and breast-feeding is not recommended for purposes other than lysine deficiency. Consult a health care practitioner if you are considering taking lysine while pregnant or breast-feeding.
Do not use lysine if you:
- are allergic to lysine
- have liver problems
- have kidney problems
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.