Admelog and Humalog contain the same active ingredient, insulin lispro, and work the same way in your body. They are not, however, identical products. Admelog is what the FDA classifies as a “follow-on” insulin to Humalog, meaning it was developed to copy Humalog but went through its own approval process and is made by a different manufacturer. Think of it like a store-brand version of a name-brand product: same recipe, different maker, and a few practical differences worth knowing about.
Same Molecule, Different Approval Path
Both Admelog and Humalog are rapid-acting insulin lispro at a concentration of 100 units per mL. Humalog, made by Eli Lilly, has been on the market since 1996. Admelog, made by Sanofi, was approved by the FDA in 2017 through a pathway called 505(b)(2), which allows a new product to rely partly on the safety and efficacy data of an existing drug. This makes Admelog a “follow-on” biologic rather than a true biosimilar or a generic. The distinction matters mostly for how pharmacies and insurers handle it.
How They Perform Head to Head
The SORELLA 1 clinical trial directly compared Admelog and Humalog in 507 adults with type 1 diabetes over 52 weeks. Both groups also used a long-acting insulin. After 26 weeks, the Admelog group saw their HbA1c drop by 0.42%, while the Humalog group dropped by 0.47%, a difference so small it confirmed the two are therapeutically equivalent. Fasting blood sugar, after-meal glucose spikes, and daily insulin dose requirements were all similar between the two groups through the full year of the study.
Rates of low blood sugar episodes, side effects, and immune responses (the body producing antibodies against the insulin) also did not differ. For practical purposes, the two insulins do the same job equally well.
Onset, Peak, and Duration
Both products start working within 10 to 15 minutes after injection, peak between 1 and 3 hours, and wear off after about 3 to 5 hours. This rapid-acting profile makes them mealtime insulins, meant to be taken shortly before or just after eating to manage the blood sugar spike from food. There is no clinically meaningful difference in how fast or how long they work.
Who Can Use Each One
Admelog is FDA-approved for adults with type 1 or type 2 diabetes and for children aged 3 and older with type 1 diabetes. It is not approved for children under 3 or for children with type 2 diabetes. Humalog carries the same age indication for type 1 diabetes in children 3 and up. If you’re considering a switch for a child, the approved uses are the same.
Pen Devices and Concentrations
This is one area where the two brands genuinely differ. Admelog comes as a vial and as the Admelog SoloStar pen, which delivers up to 80 units per dose. Humalog offers more options: vials, cartridges, the KwikPen, the KwikPen Junior (which dials in half-unit increments for more precise dosing), and the Humalog Tempo pen. Humalog also comes in a U-200 concentration (200 units per mL) via the KwikPen 200, which holds twice as much insulin per pen and means fewer injections for people who take large doses. Admelog does not have a U-200 option.
If you rely on a specific pen device or need the U-200 concentration, switching between brands isn’t as simple as swapping one for the other. You’d need to get comfortable with a different pen design and potentially adjust your routine.
Storage Is Identical
Once opened or in use, both Admelog and Humalog (vials, pens, and cartridges) stay good for 28 days at room temperature, up to 86°F (30°C). Unopened, both should be refrigerated. There is no difference in how you store or handle them day to day.
Can Your Pharmacist Just Switch Them?
No. Because Admelog is classified as a follow-on product and not as an “interchangeable” biologic, a pharmacist cannot automatically substitute it for Humalog the way they might swap a brand-name pill for its generic. If your insurance prefers Admelog over Humalog (or the other way around), your doctor would need to write a new prescription for the preferred product. No insulin lispro product currently holds an FDA interchangeability designation.
In practice, insurers often place one of these insulins on a preferred formulary tier, which means lower copays for that product. Your out-of-pocket cost can vary significantly depending on which one your plan favors, so it’s worth checking with your insurer before assuming one is cheaper.
Price Differences Are Complicated
Admelog was positioned as a lower-cost alternative to Humalog, and its list price has historically been lower. In 2019, Admelog’s list price per unit was about 37% less than Humalog’s ($20.39 vs. $32.18 per unit, as reported in JAMA Health Forum). But list price is not what most people actually pay. After insurance negotiations and rebates, Humalog’s net price was actually slightly lower than Admelog’s that same year ($10.44 vs. $12.54). This happened because insurers treated both as branded products and negotiated discounts separately for each, rather than substituting one for the other the way they would with a true generic.
Pricing has continued to shift since then, with several manufacturers cutting insulin list prices. Your actual cost depends on your insurance plan, pharmacy, and whether you use any manufacturer discount programs. The sticker price on either product is rarely what you’ll pay at the counter.
Switching Between the Two
If you’re switching from Humalog to Admelog (or vice versa), the transition is typically straightforward because the dosing is the same unit for unit at the U-100 concentration. You won’t need to recalculate your mealtime doses. The main adjustments involve getting used to a different pen device if you’re switching from a KwikPen to a SoloStar, and confirming that your new prescription matches your current regimen. Many people switch between these two without noticing any difference in blood sugar control.