Insulin: Independent Evidence on Types, Hypos, Errors & Price

Table of contents

• Evidence summary
• What insulin is
• How it works
• What it is prescribed for
• What works and what does not
• Benefits by claim
• Risks and all side effects
• All interactions
• Who should avoid insulin
• Dosage and how to take it
• Follow the money: who makes it and who funded the evidence
• Related research
• Frequently asked questions
• Sources and funding notes

Evidence summary

Independent evidence and credibility scorecard

Independence tiers: 1 = regulator or government body; 2 = academic, Cochrane or charity-funded team with no declared commercial funding for the work (or only donated supplies); 3 = independent authors with declared industry funding from a company with a stake in the result; 4 = manufacturer-funded or manufacturer-authored. Credibility runs from A (highest) to D.

Our sources cluster in the US (five of twelve) and Europe, with one intergovernmental body. Evidence on the core questions comes from sources with opposing interests, and they agree. Government regulators, NIH-funded GRADE, charity-funded and university Cochrane reviewers, and the manufacturer's own trials all show the same thing: insulin lowers glucose well, and hypoglycaemia is the main price of that. Analogue insulins buy a modest reduction in hypos, not better HbA1c. That convergence is the strongest signal in this review. The newest products (degludec, icodec) still rely mostly on manufacturer-funded trials.

What insulin is

Insulin is a hormone normally made by the pancreas. As a medicine it is "used to take the place of insulin that is normally produced by the body" (MedlinePlus). It is injected under the skin or given through a pump. All insulins work the same way and differ mainly in how quickly they start and how long they last (MedlinePlus).

The main types

• Rapid-acting analogues (lispro, aspart, glulisine): injected with meals. NICE recommends them over soluble human insulin for mealtime use in adults with type 1 diabetes (NICE NG17, 1.7.10).
• Short-acting (soluble or "regular") human insulin: for example Humulin R and Novolin R. It can also be given into a vein in hospital (MedlinePlus).
• Intermediate-acting human insulin: isophane, also called NPH (Humulin N, Novolin N). It is the cheapest basal insulin and is on the WHO list alongside soluble human insulin (WHO EML).
• Long-acting analogues: glargine (100 and 300 units/ml), detemir and degludec. In the UK, Levemir (detemir) is being discontinued, with supply expected to end in December 2026 (NICE NG17).
• Once-weekly basal insulin: icodec (Awiqli), authorised in the EU on 17 May 2024 for adults with type 1 or type 2 diabetes (EMA). In the US, the FDA approved it (as insulin icodec-abae) in March 2026 for adults with type 2 diabetes only (FDA-approved Awiqli label, DailyMed).
• Pre-mixed (biphasic) insulins: fixed mixtures of a short or rapid insulin with an intermediate one, such as Humulin 70/30 (MedlinePlus).

Biosimilars

A biosimilar is a near-copy of a biological medicine that has been shown to have "no clinically meaningful differences" from the original (Semglee label). On 28 July 2021 the FDA approved Semglee (insulin glargine-yfgn, from Mylan). It was the first biosimilar to be judged "interchangeable" with its reference product (FDA approval letter). The original glargine, Lantus, was approved in the US on 20 April 2000 with Sanofi as the applicant (Drugs@FDA).

In the UK, NICE says to use the lowest-cost product when a biosimilar exists, and to prescribe insulin by brand name (NICE NG17, 1.7.5 and 1.7.9). The MHRA warned in 2015 that switching to biosimilar glargine (Abasaglar) may need a dose change for some people (MHRA Drug Safety Update).

Legal status

Every product in this article is a regulated medicine approved for diabetes by the FDA, the EMA or the MHRA, and used under clinical supervision. We could not verify current US over-the-counter rules for human insulin from an FDA page, so we do not describe them.

How it works

Insulin moves sugar from the blood into tissues where it is used for energy and "stops the liver from producing more sugar" (MedlinePlus). In type 1 diabetes the body makes little or no insulin, so replacing it is essential. In type 2 diabetes the body makes insulin but cannot use it well, and production falls over time.

Analogues are insulin molecules with small changes in structure. These change how fast they are absorbed from under the skin. Rapid-acting analogues are absorbed faster, to match a meal. Long-acting analogues release slowly to give a flatter background level. Icodec is designed to be injected once a week. These features are proven in human pharmacology studies. Whether they translate into fewer complications or longer lives is a separate question, covered below.

Insulin also moves potassium into cells, which can lower blood potassium. That is why the label warns about hypokalaemia (FDA-approved label, section 5.6).

What it is prescribed for

Type 1 diabetes

Everyone with type 1 diabetes needs insulin. NICE recommends multiple daily injection basal–bolus regimens as "the insulin injection regimen of choice" for adults with type 1 diabetes (NICE NG17, 1.7.1). NICE's first choice of basal insulin is twice-daily detemir. Alternatives include once-daily glargine, or degludec where night-time hypos are a particular concern (1.7.3–1.7.4). NICE is reviewing this because detemir is being withdrawn.

Type 2 diabetes

NICE's February 2026 update places insulin as one option after other medicines. If a DPP-4 inhibitor is unsuitable or fails, NICE suggests adding a sulfonylurea, pioglitazone "or an insulin-based treatment" (NICE NG28, further medication). NICE notes that insulin can increase hypoglycaemia and weight gain. It sees two main roles: acute high blood sugar, and long-term worsening glucose that does not respond to other treatments. As first insulin, NICE recommends basal insulin once or twice a day. When several basal insulins, including biosimilars, are equally suitable, it says to "use the least expensive option" (NICE NG28, 1.33–1.34).

Other uses

Insulin is also used in hospitals, given into a vein, and in diabetes during pregnancy. Our separate review covers type 2 diabetes prevention and management.

What works and what does not

Benefits by claim

Blood sugar control in type 2 diabetes

The cleanest head-to-head evidence is GRADE, run by the US National Institute of Diabetes and Digestive and Kidney Diseases. It randomised 5,047 people already on metformin to one of four drugs and followed them for an average of five years. Glargine and liraglutide were "significantly, albeit modestly, more effective" at keeping HbA1c on target than glimepiride or sitagliptin (GRADE). Severe hypoglycaemia occurred in 1.3% of people on glargine, against 2.2% on glimepiride, 1.0% on liraglutide and 0.7% on sitagliptin. Heart attacks, strokes and deaths did not differ much between groups (GRADE outcomes). In plain terms, basal insulin is one of the most effective ways to lower glucose. It does not carry the heart and kidney benefits seen with some newer tablets and injections.

Are long-acting analogues better than NPH human insulin?

This is the biggest money question in insulin, because analogues cost more. The 2020 Cochrane review for type 2 diabetes pooled 24 trials. HbA1c changes were "comparable" between analogues and NPH (Semlitsch 2020). Glargine and detemir led to fewer people having hypoglycaemia. But serious hypos were rare: for detemir, about one in 100 people benefited. Death, complications and quality of life were "insufficient or lacking" in almost all trials. Many trials also aimed for near-normal glucose targets that are tighter than current guidelines advise.

The 2021 Cochrane review for type 1 diabetes found similar HbA1c with detemir, glargine and NPH (mean differences 0.01 to 0.02 percentage points). Severe hypos fell from 11.5% to 8.5% with detemir (RR 0.69, 95% CI 0.52 to 0.92, moderate certainty). Glargine's reduction (10.2% vs 12.5%) was not statistically clear. The authors found "no evidence of a clinically relevant difference" between the analogues themselves. They also found no trials of degludec against NPH (Hemmingsen 2021). That review was funded by the Helmsley Charitable Trust, whose ACCISS project campaigns for affordable insulin.

Independent researchers have argued that treating analogues as essential medicines needs more evidence and lower prices (Beran 2019). WHO did add long-acting analogues in 2021, and the list now includes them alongside human insulin (WHO EML).

Degludec and weekly icodec

DEVOTE, funded by Novo Nordisk, randomised 7,637 people with type 2 diabetes at high cardiovascular risk to degludec or glargine. Heart attack, stroke or cardiovascular death occurred in 8.5% versus 9.3% (HR 0.91, 95% CI 0.78 to 1.06), so degludec was no worse for the heart. Severe hypoglycaemia was lower: 4.9% versus 6.6%, an absolute difference of 1.7 percentage points (DEVOTE). It was double-blind, which reduces bias, but the maker of the tested drug funded and helped run it.

For icodec, the Novo Nordisk-funded ONWARDS 1 trial randomised 984 insulin-naive people with type 2 diabetes. Icodec lowered HbA1c slightly more than daily glargine (difference −0.19 percentage points). Combined clinically significant or severe hypos were 0.30 versus 0.16 events per person-year (rate ratio 1.64, 95% CI 0.98 to 2.75 at week 52) (ONWARDS 1). In type 1 diabetes, ONWARDS 6 found icodec non-inferior to degludec on HbA1c, but hypos were nearly twice as frequent: 19.9 versus 10.4 events per patient-year (ONWARDS 6). The EMA reflects this. It says people with type 1 diabetes "should therefore only be started" on icodec if there are clear benefits from weekly dosing (EMA).

Pens, pumps and closed-loop systems

Insulin comes in vials with syringes, prefilled pens, cartridges and pumps (MedlinePlus). NICE recommends pumps (continuous subcutaneous insulin infusion) for some adults with type 1 diabetes under its technology appraisal TA151 (NICE NG17). NICE recommends hybrid closed-loop systems, which link a pump to a glucose sensor. They are for adults with type 1 diabetes whose HbA1c is 58 mmol/mol (7.5%) or more, or who have disabling hypoglycaemia despite best management, and for children and young people. The rollout runs over five years, at a price agreed with NHS England (NICE TA943). Device makers fund much of the trial evidence behind these systems. We did not grade their funding separately here.

Risks and all side effects

Other side effects

The FDA-approved glargine label lists hypoglycaemia, allergic reactions, injection-site reactions, lipodystrophy, itching, rash, oedema and weight gain as common adverse reactions (label). MedlinePlus adds skin thickening or dents at injection sites, and constipation. It lists signs of a serious allergic reaction: whole-body rash, wheezing, difficulty breathing, fast heartbeat (MedlinePlus). The label also warns that localised cutaneous amyloidosis (lumps of protein deposits) can form at injection sites. Injecting into these areas has caused high glucose, and a sudden switch to an unaffected site has caused hypoglycaemia.

Lipohypertrophy and injection technique

Lipohypertrophy is a rubbery swelling of fat under the skin from repeated injections in one spot. In the Injection Technique Questionnaire (13,289 people in 42 countries), health professionals found it in 30.8% of patients. People with it used 10.1 more units of insulin a day and had HbA1c 0.55 points higher. It was linked to unexplained hypos, poor site rotation and reuse of pen needles (Frid 2016). Most authors worked for BD, which sells pen needles. The survey cannot prove cause and effect.

The independent evidence that teaching better technique fixes the problem is thin. A Japanese meta-analysis (no competing interests declared) found only three trials (637 people). Education may slightly reduce total daily insulin dose (mean difference −6.26 units). Its effect on HbA1c and hypoglycaemia was very uncertain (Ichikawa 2022). NICE still advises rotating injection sites and avoiding repeated injections at the same point (NICE NG17, 1.7.19; NG28, 1.32.1).

Dosing errors: what the NPSA alert found

England's National Patient Safety Agency reviewed 16,600 insulin incidents reported from NHS providers in England and Wales between 2003 and 2009. About 24% caused harm, and 18 had fatal or severe outcomes. Wrong dose, omitted or delayed doses and the wrong insulin product made up 60% of incidents (Cousins 2011). Badly written "U" or "IU" could be read as "0" or "10", causing 10-fold and 100-fold overdoses. The NPSA's 2010 Rapid Response Report said "unit" should never be abbreviated. It also said intravenous syringes, which are marked in millilitres, should never be used to measure insulin. The agency also developed patient-held information about each person's insulin products.

Newer insulin strengths created new risks. The MHRA warned that one dose step on some 200 units/ml pens equals 2 units of insulin. It told professionals to warn patients that using insulin other than as trained "may result in a dangerous overdose or underdose" (MHRA 2015). NICE cites an NHS England patient safety alert on the "risk of severe harm and death" from withdrawing insulin from pen devices with a syringe (NICE NG17, 1.7.4). We could not open the alert itself.

All interactions

Insulin has no liver-enzyme interactions of the kind seen with many tablets. But many medicines change blood sugar, so the insulin dose may need to change. The FDA-approved glargine label lists these groups (label, section 7):

• May increase hypoglycaemia risk: other diabetes medicines (including GLP-1 receptor agonists, DPP-4 inhibitors and SGLT-2 inhibitors), ACE inhibitors such as ramipril, angiotensin receptor blockers, disopyramide, fibrates, fluoxetine, MAO inhibitors, pentoxifylline, pramlintide, salicylates, somatostatin analogues such as octreotide, and sulfonamide antibiotics.
• May reduce insulin's effect: atypical antipsychotics (olanzapine, clozapine), corticosteroids, danazol, diuretics, oestrogens and oral contraceptives, progestogens, glucagon, isoniazid, niacin, phenothiazines, protease inhibitors, somatropin, sympathomimetics (salbutamol/albuterol, adrenaline/epinephrine, terbutaline) and thyroid hormones.
• Either direction: alcohol, beta-blockers, clonidine and lithium. Pentamidine can cause hypoglycaemia followed by high sugar.
• May hide hypo warning signs: beta-blockers, clonidine, guanethidine and reserpine.
• Pioglitazone and other thiazolidinediones: fluid retention and heart failure when combined with insulin (label, 5.7).

MedlinePlus notes that alcohol "may cause a decrease in blood sugar". It also advises telling your doctor about illness, stress, travel across time zones or changes in exercise, which can all change insulin needs (MedlinePlus). Supplements that lower glucose, such as berberine, may add to insulin's effect. We found no regulator data quantifying this.

Who should avoid insulin

Almost no one with type 1 diabetes can avoid insulin; stopping it can be fatal. The right question is who needs extra care:

• Anyone during a hypo: the label contraindicates insulin during episodes of hypoglycaemia and in people allergic to the product or its ingredients (label, section 4).
• Older and frail adults: hypo-related emergency visits and admissions are highest in people aged 80 and over (Geller 2014).
• Kidney or liver disease, and hypo unawareness: the label calls for more frequent glucose monitoring (label, 5.3). See our review of chronic kidney disease and the heart.
• Pregnancy: insulin is widely used in pregnancy. The glargine label notes that published studies have not shown a clear link with birth defects, and that poorly controlled diabetes carries risks for mother and baby (label, 8.1).
• Breastfeeding: data on glargine in breast milk are limited. The body's own insulin is normally present in milk (label, 8.2).
• Children: glargine products are licensed in children with type 1 diabetes. Icodec is authorised in the EU only for adults (EMA).
• People with type 1 diabetes considering icodec: more hypos than daily insulin (ONWARDS 6).
• Drivers and people in safety-critical jobs: follow DVLA or local licensing rules (DVLA).
• Surgery: tell the surgeon or dentist that you use insulin (MedlinePlus).

Dosage and how to take it

Insulin doses are individual and must be set and adjusted with a clinician. We report only label and guideline information here. This is not dosing advice.

• Label starting dose, type 2 (glargine): "0.2 units/kg or up to 10 units once daily" for people not already on insulin (Semglee label, 2.3).
• Label starting dose, type 1 (glargine): about one-third of total daily insulin needs, with mealtime insulin making up the rest. In type 1 it "must be used concomitantly with short-acting insulin".
• Switching: moving from glargine 300 units/ml to 100 units/ml starts at 80% of the previous dose, according to the label. Any switch of strength, maker, type or injection site should happen under close medical supervision (label, 2.4 and 5.2).
• Icodec: one injection under the skin of the belly, thigh or upper arm "once a week, on the same day each week" (EMA).
• Technique: rotate injection sites to reduce lipodystrophy and amyloidosis (label, 2.1). Never draw insulin out of a pen with a syringe, and never measure insulin with an intravenous syringe (NPSA).
• Storage: after opening, the Semglee label allows 28 days. Opened pens are kept at room temperature, not refrigerated (label, section 16).
• Education: NICE recommends structured education for adults with type 2 diabetes starting insulin. It covers injection technique, self-monitoring, dose titration, managing hypos and DVLA rules (NICE NG28, 1.32.1).

Follow the money: who makes it and who funded the evidence

A century-old drug, three dominant sellers

WHO notes that insulin's discoverers sold the patent for one dollar 100 years ago. Its Director-General said that gesture "has been overtaken by a multi-billion-dollar business". WHO's 2021 report found three multinational companies control more than 90% of the global insulin market. It also found that about one in two people needing insulin for type 2 diabetes do not get it, and that analogues cost at least 1.5 times as much as human insulin (WHO news release; full report).

• Novo Nordisk (Bagsværd, Denmark) makes NovoLog/NovoRapid (aspart), Levemir (detemir), Tresiba (degludec), Novolin human insulins and Awiqli (icodec) (EMA). Its controlling shareholder is Novo Holdings, which manages the assets of the Novo Nordisk Foundation (Novo Holdings). The foundation says Novo Holdings exists to give it "a satisfactory financial return" (Novo Nordisk Foundation).
• Eli Lilly (Indianapolis, US) makes Humalog (lispro), Humulin human insulins and Rezvoglar, a glargine biosimilar.
• Sanofi (Paris, France) makes Lantus and Toujeo (glargine) and Apidra (glulisine). Sanofi Aventis US holds the US Lantus licence (Drugs@FDA).
• Biosimilar makers include Mylan, now selling Semglee with Biocon Biologics listed on the current label (label).

US prices, caps and rationing

A RAND analysis funded by the US Department of Health and Human Services found that US gross insulin prices in 2022 were nearly ten times those in 33 OECD comparison countries. After US rebates, the US still paid $2.33 for every dollar paid elsewhere. Insulin is among the most heavily rebated drugs, but that does not help uninsured people or those with high deductibles who pay list prices (ASPE/RAND 2024).

High prices have a human cost. In 2017, 25.5% of 199 patients at the Yale Diabetes Center reported using less insulin than prescribed because of cost. Those who did were more likely to have poor glucose control (43.1% vs 28.1%) (Herkert 2018; funded by Yale student research awards, with authors supported by NIH). Using the CDC's 2021 National Health Interview Survey, Gaffney and colleagues estimated that 16.5% of US insulin users, about 1.3 million adults, skipped, reduced or delayed insulin because of cost (Gaffney 2022).

Deaths have been documented. Minnesota's legislature records that Alec Smith died in 2017, aged 26, after rationing insulin to get to payday: he had $1,000 in his account but needed $1,300 for insulin. The state's Alec Smith Insulin Affordability Act, in force from July 2020, lets people in urgent need get a 30-day supply for no more than $35. It requires insulin makers to supply it, with fines for non-compliance (Minnesota House).

Federal action followed. Under the Inflation Reduction Act, Medicare out-of-pocket costs for insulin have been capped at $35 per monthly prescription since 1 January 2023 for Part D, and since 1 July 2023 for Part B. HHS estimated that 1.5 million Medicare beneficiaries would have benefited had the cap applied in 2020, saving about $500 each a year. About 36% of insulin fills for uninsured people and 35% for privately insured people also had cost-sharing above $35 (ASPE 2023). That analysis came from the administration that championed the law, which gives it an interest in the result.

The three makers then announced US list-price cuts in March 2023. These are company announcements, not independent data. Lilly said it would cut Humalog and Humulin list prices by 70% and cap out-of-pocket costs at $35 a month (Lilly, 1 March 2023). Sanofi said it would cut Lantus's list price by 78% and Apidra's by 70% from 1 January 2024, with a $35 cap for commercially insured Lantus users (Sanofi, 16 March 2023). Novo Nordisk says it lowered US prices of selected insulins "by up to 75%" in 2024 (Novo Nordisk US).

Biosimilars and price

Competition appears to help. A study of 28 European countries found the median price of glargine fell 21.6% over a decade. In 2022 the median was €9.0 for Lantus, €8.9 for Abasaglar and €7.0 for Semglee. The original's price fell after biosimilars arrived (Morolla 2025). A 2016 survey in 13 low- and middle-income countries found median patient prices of $9 for human insulin and $34–44 for analogues per 10 ml. A low-paid worker needed 4 to 7 days' wages for one vial (Ewen 2019). Both studies were funded by the Helmsley Charitable Trust through Health Action International's ACCISS project, which campaigns on insulin access. That funder has no product to sell but does have a cause.

Who funded the trials

The trials behind degludec (DEVOTE) and icodec (ONWARDS 1 and 6) were funded by Novo Nordisk. ONWARDS 6 lists Novo employees who hold Novo stock among the authors, and other authors report fees from several insulin makers (ONWARDS 6). GRADE was government-funded, but Novo Nordisk and Sanofi were among the companies donating medicines and supplies (GRADE full text). The injection technique survey was mainly authored by BD staff (Frid 2016). On the independent side, the type 1 Cochrane review and the price studies were funded by the Helmsley Charitable Trust. The type 2 Cochrane review was publicly funded through Germany's IQWiG and Federal Ministry of Education and Research.

Related research

For wider, evidence-graded context, see these Pure City Research guides:

• Type 2 diabetes: prevention and management evidence
• Diabetes and heart disease: cardiovascular risks and treatment purposes
• Chronic kidney disease and the heart
• Diabetes supplements: benefits, limits and safety
• Berberine: glucose evidence, formulations and safety
• Psyllium husk: cholesterol, blood sugar and safety
• Ramipril: uses, kidney monitoring and safety
• Lithium: independent evidence on bipolar, suicide and kidney risk

Frequently asked questions

Sources and funding notes

What we could not verify: we could not open the NPSA's 2010 Rapid Response Report itself and relied on the NPSA authors' review (Cousins 2011). We could not open the NHS England patient safety alert on withdrawing insulin from pens; we cite NICE's reference to it. Two pages blocked automated access: the US Senate Finance Committee's 2021 insulin pricing report and Lilly's March 2023 press release. We do not quote the Senate report's findings, and Lilly's price-cut details come from the release headline and search-result summaries of it. We could not find the funding statement for the Gaffney 2022 survey. We could not confirm current US over-the-counter rules for human insulin, or company-specific global insulin revenues. The WHO's "more than 90%" market-share figure dates from 2021. Rationing deaths beyond the documented case of Alec Smith were not verified from primary sources. Evidence on hybrid closed-loop systems was taken from NICE's appraisal; we did not grade the device trials' funding.

1. MedlinePlus: Human insulin injection — US National Library of Medicine patient information (AHFS content, ASHP); public.
2. Semglee (insulin glargine-yfgn) FDA-approved prescribing information, 2024 — written by the maker, approved by the FDA; class information for insulin glargine.
3. FDA approval letter, BLA 761201 (Semglee), 28 July 2021 — US regulator; first interchangeable determination.
4. Drugs@FDA: Lantus, BLA 021081 — US regulator record; Sanofi Aventis US.
5. Awiqli (insulin icodec-abae) FDA-approved prescribing information, DailyMed (revised March 2026) — written by the maker, approved by the FDA; initial US approval 2026, type 2 diabetes only.
6. European Medicines Agency: Awiqli (insulin icodec) — EU regulator; authorisation holder Novo Nordisk A/S.
7. MHRA Drug Safety Update: high-strength, fixed-combination and biosimilar insulins (April 2015) — UK regulator.
8. NICE NG17: Type 1 diabetes in adults (last updated 17 August 2022, with 2026 detemir notice) — UK guideline; NICE (public body).
9. NICE NG28: Type 2 diabetes in adults, insulin-based treatments (last updated 18 February 2026) — UK guideline; NICE. Also further medication.
10. NICE TA943: Hybrid closed loop systems for type 1 diabetes — UK technology appraisal; NICE.
11. DVLA: Diabetes mellitus, assessing fitness to drive — UK government.
12. WHO Model List of Essential Medicines: insulins — WHO (member states and voluntary contributions).
13. WHO news release on insulin access report (12 November 2021) and Keeping the 100-year-old promise — WHO.
14. Semlitsch T et al. (Ultra-)long-acting insulin analogues versus NPH insulin for adults with type 2 diabetes. Cochrane 2020 — systematic review; Medical University of Graz and Goethe University Frankfurt; funded by IQWiG and the German Federal Ministry of Education and Research; one author with industry fees (full text).
15. Hemmingsen B et al. (Ultra-)long-acting insulin analogues for people with type 1 diabetes. Cochrane 2021 — systematic review; Helmsley Charitable Trust (ACCISS).
16. GRADE Research Group. Glycemia reduction in type 2 diabetes — glycemic outcomes. N Engl J Med 2022 — randomised trial; NIDDK with donated supplies (full text). Also microvascular and cardiovascular outcomes.
17. Marso SP et al. Efficacy and safety of degludec versus glargine in type 2 diabetes (DEVOTE). N Engl J Med 2017 — randomised trial; funded by Novo Nordisk.
18. Rosenstock J et al. Weekly icodec versus daily glargine U100 in type 2 diabetes without previous insulin (ONWARDS 1). N Engl J Med 2023 — randomised trial; funded by Novo Nordisk.
19. Russell-Jones D et al. Icodec versus degludec in type 1 diabetes (ONWARDS 6). Lancet 2023 — randomised trial; funded by Novo Nordisk; Novo employee authors.
20. Geller AI et al. National estimates of insulin-related hypoglycemia and errors leading to emergency department visits and hospitalizations. JAMA Intern Med 2014 — US CDC surveillance study.
21. Cousins D et al. Insulin, hospitals and harm: a review of patient safety incidents reported to the NPSA. Clin Med 2011 — NPSA authors; no funding statement shown.
22. Frid AH et al. Worldwide Injection Technique Questionnaire Study: injecting complications. Mayo Clin Proc 2016 — survey; three of five authors affiliated with BD.
23. Ichikawa M et al. Education on injection technique for patients with lipohypertrophy: systematic review and meta-analysis. BMJ Open 2022 — Japanese academic authors; no competing interests declared.
24. ASPE/RAND. Comparing insulin prices in the United States to other countries: 2022 data (February 2024) — funded by US HHS (contract HHSP233201500038I).
25. ASPE. Insulin affordability and the Inflation Reduction Act (January 2023, revised October 2023) — US HHS.
26. Herkert D et al. Cost-related insulin underuse among patients with diabetes. JAMA Intern Med 2019 (online December 2018) — Yale student research awards; NIH support for authors.
27. Gaffney A, Himmelstein DU, Woolhandler S. Prevalence and correlates of patient rationing of insulin in the United States. Ann Intern Med 2022 — survey analysis; funding statement not accessible.
28. Minnesota House of Representatives: Alec Smith Insulin Affordability Act (2020) — state legislature.
29. Morolla D et al. Biosimilar introduction and insulin glargine prices in 28 European countries. BMJ Open 2025 — Helmsley Charitable Trust (HAI ACCISS).
30. Ewen M et al. Insulin prices, availability and affordability in 13 low-income and middle-income countries. BMJ Glob Health 2019 — Helmsley Charitable Trust and Stichting ICF (ACCISS).
31. Beran D et al. Analogue insulin as an essential medicine: the need for more evidence and lower prices. Lancet Diabetes Endocrinol 2019 — academic commentary.
32. Sanofi press release, 16 March 2023 — manufacturer statement.
33. Eli Lilly press release, 1 March 2023 — manufacturer statement.
34. Novo Nordisk US: access and affordability commitment — manufacturer statement.
35. Novo Holdings: about and Novo Nordisk Foundation: about — ownership statements.

Educational research reviewed 7 October 2026. This article is not medical advice; talk to a qualified clinician or pharmacist before starting, stopping or combining treatments.