FDA Approves Lilly’s Onswik, a Once-Weekly Insulin for Type 2 Diabetes

The FDA has approved Onswik (insulin efsitora alfa-gobe), Eli Lilly’s once-weekly basal insulin, for adults with type 2 diabetes. The decision, announced on September 24, 2026, means people who need background insulin can replace a daily shot with a single weekly injection — cutting basal injections from about 365 a year to 52.

What was approved

Onswik is approved, alongside diet and exercise, to improve blood-sugar control in adults with type 2 diabetes. It will come in a prefilled KwikPen in two concentrated strengths, 500 and 1,000 units per milliliter, and Lilly says it will reach US pharmacies in the coming months. It is not approved for type 1 diabetes, where trials showed a higher risk of severe low blood sugar. The US decision follows approvals in the European Union, Japan and Mexico, and a recommendation from England’s NICE for NHS use, which we covered earlier this month.

The second weekly insulin this year

Onswik is not the first. In March 2026, the FDA approved Novo Nordisk’s Awiqli (insulin icodec), also a once-weekly basal insulin for type 2 diabetes. After a century in which insulin meant at least one injection a day, US patients now have two weekly options within the same year, and the two biggest diabetes companies competing on them.

How a weekly insulin works

Natural insulin is cleared from the body within minutes, and even today’s long-acting basal insulins are engineered to last about a day. Stretching that to a week takes more radical engineering. Efsitora is a fusion protein: a modified, single-chain insulin joined to the Fc region of an antibody, the same part that lets antibodies circulate for weeks. That keeps the molecule in the bloodstream long enough to release a steady, low level of insulin activity across seven days. Icodec takes a different route, binding to the blood protein albumin to form a slowly released reservoir.

The evidence

The approval rests on four Phase 3 QWINT trials in type 2 diabetes. In people starting insulin for the first time, efsitora lowered HbA1c, the long-term blood-sugar measure, as well as daily insulin glargine (QWINT-1) and insulin degludec (QWINT-2). In people switching from a daily basal insulin, it produced a greater HbA1c reduction than degludec at one year (QWINT-3). And in people already using both basal and mealtime insulin, it matched glargine (QWINT-4). Across the program, the safety profile was similar to the daily insulins.

That design is the right one for this kind of drug. Nobody expects a weekly insulin to control blood sugar dramatically better than a well-managed daily one; the claim is that it achieves comparable control with 85% fewer basal injections, and non-inferiority against the standard insulins is precisely the evidence for that claim.

Who stands to benefit most

For many people with type 2 diabetes, the hardest part of insulin is not the injection itself but doing it every day. Missed doses are common, and some people delay starting insulin for years because a daily injection feels like a burden. Weekly dosing could help most for:

• People starting insulin, for whom a weekly shot may lower the barrier to beginning treatment at all.
• Older adults and people with limited dexterity or eyesight, who may rely on a family member or visiting nurse to inject — a daily visit becomes a weekly one.
• People who often forget doses, since a steady weekly level is more forgiving than a missed daily injection.

Where basal insulin fits in type 2 treatment

Most people with type 2 diabetes start with lifestyle changes and pills such as metformin, then often add a GLP-1 drug or an SGLT2 inhibitor. Insulin usually comes in when those are not enough to bring HbA1c to target, because type 2 diabetes tends to progress as the pancreas makes less insulin over time. Basal insulin provides a steady background level between meals and overnight; some people later also need mealtime insulin. Onswik replaces only the basal part. People who also inject at meals would still do so, as in QWINT-4, though their total number of injections would still fall.

The trade-offs

A dose that lasts a week also can’t be taken back for a week. If a person gets sick, stops eating, or changes their activity sharply, a daily insulin can be reduced the next day; a weekly one keeps working. That is one reason type 1 diabetes, where there is no natural insulin production to buffer mistakes, was left off the label. Weekly insulins also require patients and clinicians to learn new dosing and adjustment habits, and switching from a daily insulin takes care. Lilly has not yet disclosed US pricing, and coverage by insurers will shape how quickly it is used.

What it means for diabetes care

The approval fits a wider shift toward fewer, longer-acting doses in metabolic disease — weekly GLP-1 injections, daily GLP-1 pills, and now weekly insulin. Lilly is also studying efsitora alongside its GLP-1 drugs, and a future where a person with type 2 diabetes takes one weekly insulin and one weekly GLP-1 treatment is increasingly realistic. For now, Onswik gives prescribers and patients a second weekly option and a real choice between the two approaches. This is regulatory news, not medical advice; changes to insulin treatment should be made with a clinician.