Insulin (Humulin, Lantus, and analogs)

Summary

Insulin is the peptide hormone that lets cells take up glucose (blood sugar), and injected insulin has been an approved, life sustaining treatment for diabetes since 1923, with recombinant human insulin (made by engineered microbes) approved in 1982 and long and rapid acting analogs (modified versions) from 1996 onward. Landmark randomized trials showed that intensive insulin therapy (tight blood sugar control) reduces retinopathy (eye damage), kidney disease, and neuropathy (nerve damage) by 25 to 76% in type 1 diabetes (DCCT) and microvascular complications (damage to small blood vessels) by 25% in type 2 diabetes (UKPDS), at the cost of more hypoglycemia (low blood sugar) and weight gain. It is prescription only in the US except for older human insulins sold over the counter, and it is prohibited by WADA for athletes without a therapeutic use exemption, a documented medical permission to use it.

What is Insulin?

Insulin is a 51 amino acid peptide hormone (two chains linked by disulfide bonds) and its recombinant analogs. It is also known as Human insulin, Insulin analogs, Insulin glargine, Insulin lispro, Insulin aspart, Insulin degludec, Humulin, Novolin, Lantus, Humalog, NovoLog.

How does it work?

Insulin binds the insulin receptor tyrosine kinase on muscle, fat, and liver cells, triggering GLUT4 translocation and glucose uptake, promoting glycogen and fat storage, and suppressing hepatic glucose output and lipolysis. Analogs alter the amino acid sequence or add fatty acid chains to change absorption speed: rapid acting analogs (lispro, aspart, glulisine) act within 15 minutes, while basal analogs (glargine, detemir, degludec) provide flat coverage for 24 hours or longer.

FDA-approved uses of Insulin

Yes. Human insulin and insulin analogs (modified versions) are FDA approved to improve glycemic control (blood sugar control) in adults and children with diabetes mellitus, per the Humulin R and Lantus labels; Lantus is not recommended for diabetic ketoacidosis, a dangerous acid buildup from severe insulin shortage. Regular and NPH human insulins (the older, unmodified types) can be bought without a prescription in most states, but analog insulins such as glargine and lispro are prescription only. Since March 2020 insulins are regulated as biologics, drugs made in living cells. [4] [5]

What does the evidence say about Insulin?

Among the strongest evidence bases in medicine. DCCT (n = 1,441, mean 6.5 years) showed intensive insulin therapy in type 1 diabetes reduced the onset of retinopathy by 76%, progression by 54%, microalbuminuria by 39%, and neuropathy by 60%, with a two to three fold increase in severe hypoglycemia. UKPDS 33 (n = 3,867, median 10 years) showed intensive glucose control with sulfonylureas or insulin in type 2 diabetes reduced microvascular endpoints by 25%. ORIGIN (n = 12,537, median 6.2 years) showed basal insulin glargine was neutral for cardiovascular outcomes in people with dysglycemia, with more hypoglycemia and about 1.6 kg weight gain.

Human evidence

DCCT 1993: 1,441 patients with type 1 diabetes randomized to intensive (three or more injections or pump, HbA1c about 7%) or conventional therapy (HbA1c about 9%) for a mean 6.5 years; intensive therapy cut retinopathy onset by 76%, retinopathy progression by 54%, microalbuminuria by 39%, and clinical neuropathy by 60%, with severe hypoglycemia about three times more frequent. UKPDS 33 1998: 3,867 newly diagnosed type 2 patients; intensive policy achieved HbA1c 7.0% versus 7.9% and reduced any diabetes related endpoint by 12% and microvascular endpoints by 25%. ORIGIN 2012: 12,537 people with prediabetes or early type 2 diabetes and cardiovascular risk randomized to insulin glargine or standard care for a median 6.2 years; cardiovascular outcomes were neutral (hazard ratio 1.02), severe hypoglycemia rose from 0.31 to 1.00 per 100 person years, and weight rose 1.6 kg.

Animal evidence

Insulin was isolated from dog and cattle pancreas in 1921 to 1922 and its glucose lowering effect established in dogs before the first human use in January 1922. Animal studies underpin the physiology; the clinical evidence base is human.

Key studies

Conditions studied

Is Insulin legal in the United States?

FDA and compounding status

FDA approved in many forms: animal derived insulins from 1923, recombinant human insulin (Humulin) in 1982, insulin lispro in 1996, glargine in 2000, and subsequent analogs and biosimilars (which transitioned to biologic regulation in March 2020, enabling interchangeable products such as Semglee). Regular and NPH human insulin are available without a prescription in most states; analogs are prescription only. Insulin is not compounded and is not on any FDA bulks list.

WADA status

WADA prohibited. Athletes subject to anti-doping testing should treat this as prohibited at all times unless the current prohibited list says otherwise.

Regulatory timeline

1. Sep 21, 2026WADA

   WADA publishes the 2027 Prohibited List

   WADA published the 2027 Prohibited List on September 21, 2026, and it takes effect January 1, 2027. The S2 peptide hormone and growth factor classes are unchanged. BPC-157 is still named under S0, and MOTS-c is still named under S4.4 as an activator of AMP-activated protein kinase. WADA added a note that many peptides without approval for human use fall under S0 or another section, and that a peptide not named on the list may still be prohibited. GLP-1 receptor agonists such as semaglutide and tirzepatide are still not on the list.

   Source: WADA 2027 Prohibited List
2. Jan 1, 2026WADA

   WADA 2026 Prohibited List takes effect

   The 2026 WADA Prohibited List took effect on January 1, 2026 and continues to prohibit the S2 peptide hormone and growth factor classes (GHRH analogs, growth hormone secretagogues, GH fragments, IGF-1 and analogs, MGF, thymosin beta-4 and derivatives, hCG and GnRH-class releasing factors in males), myostatin inhibitors, insulin and the AMPK activator MOTS-c under S4, desmopressin under S5, and BPC-157 under S0. GLP-1 receptor agonists such as semaglutide and tirzepatide are not on the list.

   Source: WADA Prohibited List
3. Jan 1, 2025WADA

   WADA 2025 Prohibited List keeps peptide hormones and growth factors banned at all times

   The 2025 WADA Prohibited List took effect on January 1, 2025. Section S2 (peptide hormones, growth factors, related substances and mimetics) covers GHRH analogs such as CJC-1295, sermorelin, and tesamorelin, growth hormone secretagogues such as ipamorelin, GHRP-2, GHRP-6, hexarelin, and ibutamoren (MK-677), growth hormone fragments such as AOD-9604, growth factors including IGF-1 and its analogs, MGF, and thymosin beta-4 (TB-500), and chorionic gonadotropin and releasing factors such as gonadorelin and kisspeptin (prohibited in males). Myostatin inhibitors such as ACE-031 fall under S4, insulin under S4 metabolic modulators, desmopressin under S5, and BPC-157 remains an S0 non-approved substance.

   Source: WADA Prohibited List

Full tracker for Insulin or the category-wide tracker.

Insulin dose on the FDA label

Doses below are quoted from the FDA label for its approved uses, plus the doses used in the pivotal trials where noted. The prescriber sets the dose; PeptideAgent does not recommend doses or protocols.

FDA labels (DailyMed). Humulin R: the dose is individualized to the route, metabolic needs, blood glucose monitoring, and glycemic goal; it is injected subcutaneously about 30 minutes before a meal, generally in a regimen with an intermediate or long acting insulin, or infused intravenously only under medical supervision. Lantus (insulin glargine): injected subcutaneously once daily at the same time each day, with an individualized dose; for adults with type 2 diabetes not already on insulin, the label's recommended starting dose is 0.2 units/kg or up to 10 units once daily. Doses are then adjusted by the prescriber.

Routes reported

What are the side effects and interactions of Insulin?

Side effects

Interactions

Contraindications

How do people access Insulin legally?

Typical cost: Out of pocket cost is capped at 35 USD per month for Medicare Part D beneficiaries since 2023 and by manufacturer programs and several state laws for commercially insured and uninsured patients. List prices for analog insulins were roughly 100 to 300 USD per vial or pen pack before 2024 list price cuts; retailer branded human insulin is about 25 USD per vial. Prices verified on the last verified date.

• Rules by state
• Verified provider directory

Frequently asked questions

Decisions about starting, stopping, or combining any treatment belong with a licensed clinician who knows your history.

From the blog

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  Peptides are short chains of amino acids. Some are FDA approved medicines, some are compounded, and many are unapproved research chemicals. Here is how to tell them apart.

Sources

Numbered citations above point to these primary sources. PubMed entries link to the indexed abstract.