What the label lists and what reports show
Metreleptin side effects
Metreleptin's FDA label: “Most common in clinical trials (≥10%): headache, hypoglycemia, decreased weight, abdominal pain.” FAERS holds 1,244 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is therapy cessation (92 reports).
- No generic listed
- Boxed warning
Check it at the source: the metreleptin FDA label on DailyMed (effective March 25, 2024, Chiesi USA, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of MYALEPT?MYALEPT may cause serious side effects, including: See "What is the most important information I should know about MYALEPT?" low blood sugar (hypoglycemia). You may get low blood sugar if you use MYALEPT with another medicine that can cause low blood sugar, such as insulin or sulfonylurea. The dose of your insulin or sulfonylurea may need to be lowered while you use MYALEPT. Signs and symptoms of low blood sugar may include: shakiness weakness hunger sweating dizziness fast heart beat headache confusion feeling jittery drowsiness irritability Talk with your healthcare provider about how to recognize and treat low blood sugar. Make sure that your family and other people around you a lot know how to recognize and treat low blood sugar. autoimmunity. People who have or have had certain problems with their immune system (autoimmune disease) may have worsening of their symptoms with MYALEPT. […]
Source: FDA drug label, Chiesi USA, Inc., effective March 25, 2024 (SPL set d3b50bbd-140b-425c-b5ec-d4682aad62bc), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common in clinical trials (≥10%): headache, hypoglycemia, decreased weight, abdominal pain.
Table 3: Adverse Reactions of 5% or Greater Incidence in Patients with Generalized Lipodystrophy Receiving MYALEPT in an Open-Label, Single-Arm Study
| Reaction | All Subjects N=48 (%) 1. Hypoglycemic events were assessed as mild, moderate, severe, or life threatening based… |
|---|---|
| Headache | 6 (13) |
| Hypoglycemia 1 | 6 (13) |
| Decreased weight | 6 (13) |
| Abdominal pain | 5 (10) |
| Arthralgia | 4 (8) |
| Dizziness | 4 (8) |
| Ear infection | 4 (8) |
| Fatigue | 4 (8) |
| Nausea | 4 (8) |
| Ovarian cyst | 4 (8) |
| Upper respiratory tract infection | 4 (8) |
| Anemia | 3 (6) |
| Back pain | 3 (6) |
| Diarrhea | 3 (6) |
| Paresthesia | 3 (6) |
| Proteinuria | 3 (6) |
| Pyrexia | 3 (6) |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedMost common in clinical trials (≥10%): headache, hypoglycemia, decreased weight, abdominal pain. ( 5.4 , 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Chiesi Farmaceutici S.p.A. at 1-888-661-9260 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 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 (14.1) ]. 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 (%) 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; …
Source: FDA drug label, Chiesi USA, Inc., effective March 25, 2024 (SPL set d3b50bbd-140b-425c-b5ec-d4682aad62bc), via openFDA; the full label on DailyMed
What do FAERS reports show?
1,244 reports list metreleptin among the medicines taken, each a report of something that happened, not proof the medicine caused it; 69 are coded as a death and 360 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 17 reactions below, 5 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Metreleptin: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions