Last updated on RxList: 1/22/2021
Myalept Side Effects Center

What Is Myalept?

Myalept (metreleptin) for Injection is a recombinant human leptin analog used as an adjunct to diet as replacement therapy to treat the complications of leptin deficiency in patients with congenital or acquired generalized lipodystrophy.

What Are Side Effects of Myalept?

Common side effects of Myalept include: 

  • headache,
  • low blood sugar,
  • weight loss,
  • abdominal pain,
  • joint pain,
  • dizziness,
  • ear infection,
  • fatigue,
  • nausea,
  • ovarian cysts,
  • upper respiratory tract infections,
  • anemia,
  • back pain,
  • diarrhea,
  • numbness and tingling,
  • high levels of protein in the urine, and
  • fever.

Dosage for Myalept

Dosage of Myalept is based on the patient's weight.

What Drugs, Substances, or Supplements Interact with Myalept?

Myalept may interact with oral contraceptives, warfarin, cyclosporine, or theophylline. Tell your doctor all medications and supplements you use.

Myalept During Pregnancy and Breastfeeding

During pregnancy, Myalept should be used only if prescribed. There is a program that monitors outcomes in women exposed to Myalept during pregnancy. Women who become pregnant during treatment are encouraged to enroll. Breastfeeding is not recommended while taking this drug.

Additional Information

Our Myalept (metreleptin) for Injection Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

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.


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Myalept Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; rapid heart rate, feeling like you might pass out; swelling of your face, lips, tongue, or throat.

In some people, metreleptin can trigger an immune response to the medicine, making it less effective or causing certain side effects. Call your doctor if you develop:

  • any signs of a new infection (such as fever, chills, mouth sores, or trouble breathing);
  • changes in your blood sugar levels (if you are diabetic); or
  • worsening of your lipodystrophy symptoms.

Also call your doctor at once if you have:

  • low blood sugar--headache, hunger, weakness, sweating, confusion, irritability, dizziness, fast heart rate, or feeling jittery; or
  • pancreatitis--severe pain in your upper stomach spreading to your back, nausea and vomiting.

Common side effects may include:

  • low blood sugar;
  • headache;
  • weight loss; or
  • stomach pain.

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.

Read the entire detailed patient monograph for Myalept (Metreleptin for Injection)


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Myalept Professional Information


Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Open-Label, Single-Arm Study

The safety of MYALEPT was evaluated in 48 patients with generalized lipodystrophy in a single-arm, open-label study [see Clinical Studies]. The median duration of exposure in this trial was 2.7 years with a range of 3.6 months to 10.9 years. The most frequent adverse reactions are summarized in Table 3.

Table 3: Adverse Reactions of 5% or Greater Incidence in Patients with Generalized Lipodystrophy Receiving MYALEPT in an Open-Label, Single-Arm Study

All Subjects
N=48 (%)
Headache6 (13)
Hypoglycemia16 (13)
Decreased weight6 (13)
Abdominal pain5 (10)
Arthralgia4 (8)
Dizziness4 (8)
Ear infection4 (8)
Fatigue4 (8)
Nausea4 (8)
Ovarian cyst4 (8)
Upper respiratory tract infection4 (8)
Anemia3 (6)
Back pain3 (6)
Diarrhea3 (6)
Paresthesia3 (6)
Proteinuria3 (6)
Pyrexia3 (6)
1. Hypoglycemic events were assessed as mild, moderate, severe, or life threatening based on the protocol specified definitions: Mild: Documentation of low plasma glucose values with no symptoms; Moderate: Presence of clinical symptoms requiring ingestion of glucose, self-alleviated; Severe: Presence of neuroglycopenic symptoms requiring assistance from others for alleviation; Life threatening: Loss of consciousness and/or requiring intervention by administration of intravenous glucose or intramuscular glucagon.

In patients with generalized lipodystrophy receiving MYALEPT in this study, less common adverse reactions included injection-site erythema and urticaria (N=2 [4%]).

Six patients (13%) had 7 adverse reactions of hypoglycemia, 6 of which occurred in the setting of concomitant insulin use, with or without oral antihyperglycemic agents.

Two patients (4%) had events of pancreatitis, both of whom had a medical history of pancreatitis.


As with all therapeutic proteins, there is potential for immunogenicity. Anti-metreleptin antibodies were detected in 84% (36/43) of generalized lipodystrophy patients studied in the MYALEPT trials. Total anti-metreleptin antibody titers ranged between 1:5 and 1:1,953,125. The incompleteness of the current immunogenicity database precludes understanding of the magnitude and persistence of the observed anti-drug antibody responses. Anti-metreleptin antibodies with neutralizing activity associated with adverse events consistent with loss of endogenous leptin activity and/or loss of MYALEPT efficacy were observed in 6% (2/33) of the patients with generalized lipodystrophy tested. Adverse events reported in these two patients included severe infections and worsening of metabolic control (increases in HbA1c and/or triglycerides). Test for anti-metreleptin antibodies with neutralizing activity in patients who develop severe infections or show signs suspicious for loss of MYALEPT efficacy during treatment. Contact Aegerion Pharmaceuticals, Inc. at 1-866216-1526 for testing of clinical samples.

The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. The immunogenicity assays utilized in clinical trials lacked sensitivity, resulting in potential underestimation of the number of samples positive for anti-metreleptin antibodies with neutralizing activity. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to metreleptin with the incidence of antibodies to other products may be misleading.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of MYALEPT. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

  • Incorrect dose administered, accidental overdose [see DOSAGE AND ADMINISTRATION]

Read the entire FDA prescribing information for Myalept (Metreleptin for Injection)

© Myalept Patient Information is supplied by Cerner Multum, Inc. and Myalept Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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