Cagrilintide: Side Effects & Safety

Cagrilintide (NN9838) is Novo Nordisk's long-acting amylin analog, designed to be administered once weekly alongside semaglutide for additive weight loss — the combination is marketed in development as CagriSema. Amylin is a hormone co-secreted with insulin by pancreatic β-cells that slows gastric emptying, suppresses postprandial glucagon, and signals satiety. Cagrilintide's safety profile shares features with other incretin-based therapies (semaglutide, tirzepatide, liraglutide) — predominantly GI effects — but also has amylin-specific considerations.^[1]

Cagrilintide is not yet FDA-approved. CagriSema (the combination) is in Phase 3 (REDEFINE program) as of 2026. Cagrilintide is not on the July 2026 FDA Pharmacy Compounding Advisory Committee 503A bulks list agenda. The cagrilintide circulating in research-peptide markets is unregulated and is not the clinical-grade molecule used in Novo Nordisk trials.

Pooled from Phase 2 dose-escalation trials (monotherapy and CagriSema combination).^[1][2]

Effect	Frequency (active arms)	Notes
Nausea	30–50%	Peaks during dose titration; severity decreases with stable dosing
Vomiting	10–25%	Dose-dependent; more common with higher doses and combination therapy
Diarrhea	15–25%	Mild to moderate, transient
Constipation	10–20%	From slowed gastric motility
Decreased appetite	20–35%	Pharmacological effect, not adverse per se
Dyspepsia / abdominal discomfort	Common	Related to delayed gastric emptying
Injection-site reactions	~5–10%	Mild, transient
Increased heart rate	Mean +2–3 bpm	Comparable to other class members
Hypoglycemia (monotherapy in non-diabetics)	Uncommon	Rises sharply when combined with insulin or sulfonylureas
Discontinuation due to adverse events	~5–15% (dose dependent)	Mostly GI-driven

The combination with semaglutide (CagriSema) produces additive GI effects rather than synergistic toxicity — total GI burden is roughly the sum of each compound's profile, with nausea remaining the most common discontinuation reason.

Most of cagrilintide's safety profile is incretin-class GI effects. There are also amylin-pathway-specific considerations:

• Gastric emptying delay can be substantial — meaningful for oral medication absorption (see drug interactions).
• Postprandial glucagon suppression changes how the body handles meals; relevant in patients with brittle diabetes.
• Bone density and pancreatic function: long-term effects of sustained amylin-receptor agonism are not fully characterized in humans. Phase 3 trials will provide more data.
• Renal function: like other GLP-1 class drugs, acute kidney injury can occur secondary to severe nausea / vomiting / dehydration rather than direct drug nephrotoxicity.

• Personal or family history of medullary thyroid carcinoma or MEN 2: the standard GLP-1 class boxed warning is generally applied to amylin/incretin combinations as a precaution. Discuss with prescriber.
• Severe gastrointestinal disease (gastroparesis, severe IBD, recurrent pancreatitis): avoid.
• Type 1 diabetes: not studied for primary glucose management.
• Severe hepatic or renal impairment: pharmacokinetics not characterized in these populations.
• Pregnancy: animal reproductive toxicity data exists for the class; contraindicated.
• Breastfeeding: insufficient data; avoid.
• Active malignancy: discuss with oncology.
• Known hypersensitivity to amylin analogs.

Drug interactions

• Insulin / sulfonylureas: reduce dose to avoid hypoglycemia (especially in diabetic patients).
• Oral medications, especially narrow-therapeutic-index drugs: delayed gastric emptying alters absorption. Clinically significant for oral contraceptives, levothyroxine, anticoagulants (warfarin), some antimicrobials. Time dosing carefully or consider alternative formulations.
• Other GLP-1 / amylin / incretin drugs: CagriSema is the intentional combination of cagrilintide + semaglutide. Other combinations (e.g., cagrilintide + tirzepatide) have not been studied and risk additive toxicity.
• Pramlintide (Symlin): pramlintide is an older approved amylin analog. Combining with cagrilintide is redundant and increases risk.

• Mild GI symptoms during titration: slow the titration schedule, eat smaller meals, avoid high-fat foods, hydrate aggressively.
• Persistent severe abdominal pain: stop and evaluate for pancreatitis (lipase, imaging).
• Persistent vomiting / dehydration: hold doses, restore volume, evaluate for gastroparesis or other GI pathology.
• Right upper quadrant pain, jaundice: evaluate for gallbladder disease (class signal).
• Hypoglycemia (in diabetic patients): reduce insulin or sulfonylurea dose; have fast-acting carbohydrate available.
• Allergic reaction: discontinue immediately and seek emergency care.

See the cagrilintide complete guide, dosage protocols, benefits and research, and the peptides for weight loss overview.