Glossary of terms

A1C test

A blood test that correlates with a person’s average blood glucose level over the span of 2-3 months.


Relating to the abdomen, or belly, the part of the body containing the digestive organs.

Bacteriostatic water for injection (BWFI)

A sterile water for injection used to mix Myalept for adults and older children. BWFI contains benzyl alcohol added as a preservative to keep bacteria from reproducing. BWFI should not be used to mix Myalept for infants.


A comprehensive program of support services and resources available to Myalept patients at no cost to them.

ByMySide Coordinator

A member of your support team who provides education about GL, Myalept, and the process of starting and staying on treatment.


A condition or disease that is present at birth, whether or not it is inherited.


A lack or shortage.

Generalized Lipodystrophy (GL)

A rare disease that results in having little to no fat tissue all over the body. Generalized means all over, Lipo means fat, and Dystrophy means abnormal loss of tissue.


Relating to something inherited from parents. If a health problem is genetic, it means you inherited the problem genes from at least one of your parents.


Also called low blood glucose, or low blood sugar, and occurs when blood glucose drops below normal levels.


A hormone that regulates the amount of glucose in the blood, or blood sugar.


A hormone that helps the body process fat.


Relating to metabolism, the biochemical processes that occur within you, such as the way your body breaks down sugar or fat.


A large organ of the body located near the stomach that plays an essential role in helping the body digest food. It also produces and secretes hormones that regulate the body’s sugar level.


Myalept Risk Evaluation and Mitigation Strategy (REMS) Program is an FDA program designed to enhance drug safety.

Sharps disposal container

A safety container that is used for the disposal of medical needles.


A type of anti-diabetic medication that acts on the beta cells of the pancreas to increase the secretion of insulin.


A type of fat (lipid) found in your blood and stored in fat cells. 

Water for injection (preservative free) (WFI)

Appropriate liquid used to mix Myalept for use in newborns or infants. 

Risk of Neutralizing antibodies and risk of lymphoma.

Important Safety Information

Myalept is only available through a restricted program called the Myalept Risk Evaluation and Mitigation Strategy (REMS) Program. Your doctor must be enrolled and certified in the program in order to prescribe Myalept.

Myalept may cause serious side effects, including:

  • risk for developing certain proteins called neutralizing antibodies that may reduce how well your own leptin or Myalept works. Side effects of these antibodies may include infection, problems with blood sugar (including diabetes), or an increase in triglycerides
  • increased risk of a type of blood cancer called lymphoma

You should not take Myalept if you:

  • have general obesity not caused by a congenital leptin deficiency
  • are allergic to metreleptin or any of the ingredients in Myalept.  Symptoms of an allergic reaction include rash, itching (hives), swelling of face, lips, tongue, or throat, problems breathing or swallowing, fainting or dizziness, rapid heartbeat.

Before using Myalept, tell you doctor if you have any medical conditions including if you:

  • have or have had problems with your blood cells, including low blood cell counts (especially your white blood cells), bone marrow, immune system, pancreas, swollen lymph nodes, lymphoma, high blood triglyceride levels, or use insulin or a sulfonylurea
  • are pregnant or plan to become pregnant as it is unknown if Myalept will harm your unborn baby. If you become pregnant while using Myalept, talk to your healthcare provider about registering with a program to collect information about the outcomes of moms and babies exposed to Myalept during pregnancy. You can enroll in the Myalept program by calling 1-855-669-2537
  • are nursing or plan to nurse. You should not nurse while you take Myalept

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Other possible side effects

The most common side effects of Myalept include headache, low blood sugar, decreased weight, and/or abdominal pain.

For newborns and infants, mix Myalept with sterile water for injection (preservative-free) (WFI). Serious side effects including death have happened in newborns or infants who have received the preservative benzyl alcohol.  Bacteriostatic water for injection contains benzyl alcohol and it should not be used to mix Myalept for newborns and infants.

You may get low blood sugar (hypoglycemia) if you take Myalept with other medicines used to lower blood sugar, such as insulin or sulfonylurea. Your doses of these medications may need to be lowered while you use Myalept. Tell your doctor right away if you experience shakiness, sweating, headache, drowsiness, weakness, dizziness, confusion, irritability, hunger, fast heartbeat, or a jittery feeling because these may be signs of low blood sugar (hypoglycemia).

Myalept may worsen symptoms caused by certain problems in your immune system (autoimmune disorder). Ask your doctor about what symptoms you should watch for that may require further testing.

Talk to your healthcare provider about any side effect that bothers you or that does not go away. These are not all the possible side effects of Myalept. For more information, speak to your doctor or pharmacist. Tell your doctor about all the medications you take, including prescription and nonprescription medicines, vitamins, and herbal supplements.  Take Myalept exactly as your doctor instructs you.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.

This is the most important information about Myalept. For more detailed information, Please see the Medication Guide and full Prescribing Information including Box Warning.

What is Myalept?

Myalept (metreleptin), a prescription medication, is a leptin replacement therapy used with a doctor-recommended diet to treat problems caused by not having enough leptin (leptin deficiency) in people with generalized lipodystrophy.

  • It is not known if Myalept is safe and effective when used to treat problems (complications) caused by partial lipodystrophy or to treat liver disease, including non-alcoholic steatohepatitis (NASH)
  • Myalept should not be used to treat people with HIV-related lipodystrophy or people with metabolic disease, including diabetes mellitus and hypertriglyceridemia, without signs or symptoms of congenital or acquired generalized lipodystrophy.

Please see the Medication Guide and full Prescribing Information including Box Warning.


Photographs on this website feature people with GL and their caregivers.