Lysine

Lysine is an amino acid (a building block of protein) and is also known as L-2,6-diaminohexanoic acid, Lisina, Lys, Lysine Hydrochloride, Lysine Monohydrochloride, and other names.

Lysine has been used in alternative medicine as a possibly effective treatment for cold sores caused by herpes simplex.

Other uses that have not been proven by research include canker sores, diabetes, stress, and improving athletic performance.

It is not clear whether lysine is effective for treating any medical condition. The FDA has not approved the medicinal use of this product. Lysine should not be used instead of medication prescribed by your doctor.

Lysine is often sold as an herbal supplement. Many herbal compounds do not have regulated manufacturing standards, and some supplements have been found to be contaminated with toxic metals or other drugs. You should buy herbal/health supplements from a reliable source to reduce the risk of contamination.

Lysine may also be used for purposes not listed in this product guide.

When thinking about using herbal supplements, talk to your doctor. You may also want to see a practitioner who knows about herbal/health supplements.

If you decide to use lysine, follow the instructions on the package or those given by your doctor, pharmacist, or other healthcare provider. Do not use more of this product than what is recommended on the label.

Do not use different forms of lysine (like tablets, liquids, and others) at the same time, unless a healthcare professional specifically tells you to. Using different forms together raises the risk of an overdose.

Call your doctor if the condition you are treating with lysine does not get better, or if it worsens while you are using this product.

Store at room temperature away from moisture and heat.

Follow all directions on the product label and package.

Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before using lysine, talk to your healthcare provider. You may not be able to use lysine if you have certain medical conditions.

Ask a doctor, pharmacist, or other healthcare provider if it is safe for you to use this product if you have:

• osteoporosis;
• lysinuric protein intolerance (in children); or
• kidney disease.

It is not known whether lysine will harm an unborn baby. Do not use this product without medical advice if you are pregnant.

It is not known whether lysine passes into breast milk or if it could harm a nursing baby. Do not use this product without medical advice if you are breast-feeding a baby.

Do not give any herbal/health supplement to a child without medical advice.

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Although not all side effects are known, lysine is thought to be possibly safe when taken for up to a year.

Common side effects of lysine may include:

• stomach pain and diarrhea.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Skip the missed dose if it is nearly time for your next scheduled dose. Do not use extra lysine to replace the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Follow your healthcare provider's instructions about any restrictions on food, beverages, or activity.

Lysine can increase how much calcium your body absorbs. Avoid taking large amounts of calcium when taking lysine.

Other drugs may interact with lysine, including prescription and over-the-counter medicines, vitamins, and herbal products. Inform all your health care providers about all medicines you are currently using and any medicine you begin or stop.

Do not take lysine without medical advice if you are using any of the following medications:

• calcium supplements; or
• gastrointestinal medicines (such as prucalopride or tegaserod).

This list is not complete. Other drugs may interact with lysine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this product guide.

• What dosage of lysine is best for herpes outbreaks?