Dulaglutide

Two DPP-4-resistant GLP-1(7-37) analogue chains are covalently linked to a modified human IgG4 Fc region via a peptide linker. The Fc portion recycles through FcRn and the sheer molecular size prevents glomerular filtration, producing a half-life of roughly five days without any fatty-acid acylation. Pharmacodynamically it is a straightforward GLP-1 agonist, but the large protein crosses into the CNS less readily than small acylated analogues, which is the usual explanation for its weaker appetite and weight effects relative to semaglutide.

Targets: GLP-1 receptor

• · 750 mcg weekly for at least 4 weeks, then 1500 mcg; 3000 and 4500 mcg are available if HbA1c targets are not met, each after at least 4 weeks.

Work out your exact syringe units →

• commonNausea— Generally milder than with semaglutide.
• commonDiarrhoea
• uncommonInjection-site reaction— Fc-fusion proteins can provoke local immune reactions.
• rarePancreatitis

• Personal or family history of medullary thyroid carcinoma or MEN2 - boxed warning.
• History of pancreatitis.
• Pregnancy.

• cautioninsulin-analogues — Hypoglycaemia risk when combined; basal insulin often needs reduction.
• cautionsulfonylureas (glimepiride, gliclazide, glipizide) — Real hypoglycaemia risk - unlike dulaglutide alone, sulfonylureas drive insulin release independently of glucose. Labels advise reducing the sulfonylurea dose when a GLP-1 agonist is started.
• redundantsemaglutide — Same receptor; semaglutide is simply more effective for weight.

• · HbA1c every 3 months.
• · Weight.
• · Renal function in diabetic kidney disease.

FDA- and EMA-approved as Trulicity for type 2 diabetes.

• Gerstein et al. 2019, REWIND cardiovascular outcomes trial, The Lancet (trial)
• AWARD phase 3 programme in type 2 diabetes (trial)
• Trulicity US prescribing information (label)

The pharmacology here is unremarkable - it is straightforward GLP-1 receptor agonism - and the interesting part is entirely about size. At roughly 60 kDa dulaglutide is about fifteen times the mass of semaglutide, which produces three consequences. It cannot be filtered by the glomerulus, so renal function is irrelevant to its clearance. It recycles through the neonatal Fc receptor, which is what gives a five-day half-life without any fatty-acid chemistry. And it does not reach central GLP-1 receptors in the hypothalamus or area postrema in any meaningful quantity, because the circumventricular organs that admit small acylated peptides do not admit a 60 kDa fusion protein nearly as readily. That last point is the whole clinical story: peripheral effects on the beta cell are preserved, so HbA1c falls properly, while the central appetite effects that produce double-digit weight loss are largely absent. Two to four kilograms is what you get, and it is not a dosing problem you can solve by going higher - REWIND used up to 1.5 mg for 5.4 years and the weight effect stayed modest. That same size explains the milder nausea profile, since area postrema signalling is what drives emesis. Dulaglutide is the clean demonstration that GLP-1 receptor agonism at the pancreas and GLP-1 receptor agonism in the brain are separable, and that the brain is where obesity drugs earn their numbers. REWIND is also notable as the only GLP-1 cardiovascular outcomes trial conducted mostly in primary prevention - about two-thirds of participants had no established cardiovascular disease - and it was still positive, which is a stronger statement than it is usually given credit for.

The main error is expecting weight loss. Two to four kilograms is the honest number, and people who chose dulaglutide because it is weekly and covered by insurance and then expected Ozempic results are systematically disappointed. The second is climbing to 3.0 and 4.5 mg chasing weight - those doses were approved on HbA1c, not on weight, and the extra nausea rarely pays. Third, injection-site reactions with an Fc-fusion protein are more often genuinely immunological than they are with small peptides, and repeated local reactions plus loss of efficacy is a signal to change molecule rather than to persist.

1. 750 mcgWeeks 1-4 — Starting dose. Note that in Japan and some other markets 0.75 mg is a maintenance dose in its own right.
2. 1.5 mgWeek 5 onward — The standard maintenance dose and the one used in REWIND.
3. 3 mgAfter at least 4 weeks at 1.5 mg — Adds roughly 0.2-0.3% more HbA1c reduction for a noticeable increase in nausea.
4. 4.5 mgAfter at least 4 weeks at 3.0 mg — Maximum dose. Genuinely diminishing returns.

• GLP-1 receptor (GLP1R) — Full agonist; each fusion protein presents two GLP-1 analogue arms, giving avidity effects that single-chain analogues do not have

  Glucose-dependent insulin secretion and glucagon suppression at the pancreas, with substantially weaker central satiety signalling because the molecule is too large to reach it.

• Neonatal Fc receptor (FcRn) — Not applicable as agonism

  pH-dependent binding in the endosome that rescues the molecule from lysosomal degradation and recycles it to the cell surface. This is the protraction mechanism, in place of albumin binding.

• REWIND Phase 3 cardiovascular outcomes · n=9901 · 281 weeks · 2019

  12% relative reduction in major adverse cardiovascular events over a median 5.4 years, in a population that was about two-thirds primary prevention.

Weeks 1-2: glycaemic effect starts. Weeks 2-4: steady state. Weeks 8-12: full HbA1c effect visible on a lab test. Months 3-6: weight effect, such as it is, plateaus at 2-4 kg. Stopping: glucose drifts back over two to three weeks.

Dulaglutide is a diabetes drug and should be treated as one. It combines sensibly with metformin, SGLT2 inhibitors and basal insulin, and the SGLT2 pairing in particular is well supported. It does not combine sensibly with any other GLP-1 agonist. If weight is the actual goal, switching molecules beats stacking - there is nothing you can add to dulaglutide that turns it into an obesity drug, because the limitation is that the molecule does not get into the brain. Cagrilintide or another amylin analogue is the only mechanistically non-overlapping addition, and there is no trial data for that pairing.

Against semaglutide: semaglutide is better on HbA1c and vastly better on weight. Dulaglutide's advantages are milder nausea and a genuinely simple ready-to-use autoinjector. Against albiglutide: same architectural idea (large fusion protein, poor CNS access, weak weight effect), and albiglutide is no longer manufactured. Against tirzepatide: not a contest on either endpoint. The reason to still care about dulaglutide is REWIND - a five-year cardiovascular benefit in a mostly primary-prevention population is evidence nothing else in the class has produced.

$150–$1000/month. US list price is roughly 900-1,000 per month; insured copays and international pricing are far lower. Market observation, not verified pricing.

• ?Protein binding is not reported in the label in a percentage form, because the protraction mechanism is FcRn recycling rather than albumin binding - the field is left null rather than guessed.
• ?The stated volume of distribution combines the label's 3.09 L central and 5.98 L peripheral compartments; there is no single reported apparent volume of distribution.
• ?The exact sequence and substitution positions of the GLP-1 analogue arms are from published descriptions and were not verified against a primary structural source.
• ?The claim that poor blood-brain barrier penetration explains the weak weight effect is the standard and most plausible explanation but has not been directly demonstrated in humans.
• ?Cost figures are market observations, not verified pricing.

• Dulaglutide and cardiovascular outcomes in type 2 diabetes (REWIND): a double-blind, randomised placebo-controlled trial Gerstein HC et al., Lancet, 2019 · PMID 31189511

  The largest and longest GLP-1 cardiovascular outcomes trial, and the only one dominated by primary prevention.

• TRULICITY (dulaglutide) injection - US prescribing information, section 12.3 Eli Lilly and Company, DailyMed

  Source for 65%/47% dose-dependent bioavailability, 3.09 L central and 5.98 L peripheral volumes, 0.142 L/h clearance, 48-hour median tmax and 2-4 week steady state.