The Differences Between Biosimilar, Human and Analog Insulins


Editor’s Note: People who take insulin require consistently affordable and predictable sources of insulin at all times. If you or a loved one are struggling to afford or access insulin, click here.

In today’s insulin market, there are categories that every type of insulin falls under. In this guide, we break down the differences between biosimilar, human and analog insulins.

What are biosimilar insulins?

Current biosimilar insulins are biologically similar to other long-acting insulins on the market. Original insulins are “FDA-approved, branded biologic used as a reference product during approval.” Biologic products are “generally large, complex molecules that are often produced through biotechnology in a living system, such as a microorganism, plant cell or animal cell.”

Today’s FDA-approved biosimilars: 

  • Semglee
  • Rezvoglar

These are intended to be easily interchanged with Lantus, a long-acting insulin by Sanofi.

Biosimilars are supposed to be interchangeable with frequently-prescribed insulin products to reduce healthcare costs. You shouldn’t need to call your prescriber in order to switch your insulin prescription with a biosimilar at the pharmacy counter. (This works in the same way as your pharmacist substituting name-brand test strips for generic ones, for example.) 

However, not all states offer interchangeable medication options. Because pharmacy laws and regulations vary from state to state, so do interchangeability standards. Some states have laws where biosimilar insulin can only be prescribed if it is lower in cost than its brand-name equivalent.

Biosimilars have “no clinically meaningful difference” from the existing FDA-approved original product, also known as a “reference product.” A reference product is a single biological product that has already been approved by the FDA. Reference products are compared against any proposed biosimilars that enter the healthcare market. Biosimilar insulins are just as safe and effective for people with diabetes to use. 

Why aren’t many biosimilar insulins available?

Biosimilar medications were first approved under section 351(K) of the Public Health Service Act for biosimilar products “shown to be biosimilar or interchangeable with an FDA-licensed reference product.” 

The U.S. Food and Drug Administration (FDA) approved the first biosimilar insulin product, Semglee, in July 2021 for people with diabetes. The second FDA-approved “Insulin glargine and insulin glargine-yfgn are biologic medications (medications made from living organisms).” ( Examples include: Toujeo SoloStar, Lantus Solostar and Basaglar KwikPen.insulin glargine biosimilar, Rezvoglar, was approved in December 2021. This is another long-acting insulin that is similar to Lantus insulin.

Despite biosimilars being attractive to patients and physicians for their safety and cost-effectiveness, there are not many biosimilars approved for use in the U.S. There is not as much information, research, awareness or availability compared to analog insulins. Few biosimilars are on the market today because of patent litigation settlements

Getting biosimilars approved is not easy because of the FDA’s rigorous standards

Since biosimilar products come from natural sources and are not exact copies, they must be thoroughly investigated and studied before they get into the hands of patients. As of February 2022, only 34 biosimilar products are approved in the U.S. However, the interest in biosimilars continues to grow throughout the world! 

What are analog insulins?

Analog insulins take up a lot more space in the healthcare market than biosimilars. Analog insulins are different from biosimilars and are used as reference products. Analog insulins are created in labs by growing insulin proteins within E-coli bacteria (Escherichia coli)—similar to how human insulins are made. They have had a greater impact on people with diabetes since the early 2000s, replacing prescription requests for many human insulins

Examples include:

  • Humalog
  • NovoRapid
  • Lantus
  • Levemir
  • Tresiba
  • Humalog Mix 25
  • Humalog Mix 50
  • NovoMix 30
  • Novolog
  • Fiasp
  • Apidra
  • Apidra SoloStar

These examples all fall into categories of insulin called Aspart, Glulisine and Lispro. Analog insulins are easily absorbed from fatty tissue, making them more predictable. Since they have a different chemical structure than human insulin, they lower your blood sugar more quickly once injected.

The first short-acting insulin that was approved for use in the U.S. in 1996 was Lispro, followed by Aspart in 2000 and Glulisine in 2004.

Analog insulins are designed to “mimic the body’s natural pattern of insulin release.” They are synthetic insulins that act like human insulin. Analog insulins can be long and fast-acting. There are also some premixed combinations available.

Learn more about the past, present and future of insulin here.

What are human insulins?

Human insulins are typically compared against analog insulins. Human insulins are made synthetically in a lab using E. coli bacteria. Until the 1980s, people with diabetes relied on cow and pig insulin, but the ability to manufacture human and analog insulin changed everything. 

Human insulin examples include:

  • Actraphane
  • Actrapid
  • Humulin N
  • Humulin R
  • Insulatard
  • Entuzity
  • Novolin
  • Novlin N
  • Novolin R
  • Afrezza
  • Insuman
  • Myxredlin

Human insulins are available in short and long-acting forms. An NPH insulin, Hagedorn, is also human insulin but it is classified as intermediate-acting. It has much slower absorption, typically taking two hours to take effect in your body and peaking in maximum effect four to six hours after the initial injection.

What are the major differences between human and analog insulins?

Human and analog insulins are administered through syringes, insulin pens and insulin pumps. (Since the currently approved U.S. biosimilar insulins are all long-acting, they are not administered through an insulin pump.) 

Human insulins are usually cheaper than analog insulins but compared to analog insulin, most human insulins lead to a more restricted lifestyle and less predictable blood sugar levels. (Afrezza, inhaled insulin, is an exception here because it is the fastest insulin on the market.)

While Walmart’s ReliOn brand offers affordable human insulins, Regular (insulin R) and NPH (insulin N), for $25 per vial, they are not a simple solution for the insulin pricing crisis.

Human insulins like Humulin/Novolin N and R require a very structured lifestyle in which you have to eat a certain number of carbs about every three hours to coincide with when these insulins peak throughout the day. The introduction of analog rapid-acting and long-acting insulins gave people with diabetes significantly more flexibility and predictability throughout the day while managing blood sugar levels.

Analog insulins take as little as 15 minutes to start working, and human insulins can take anywhere from 30 to 60. (And inhaled insulin, which is in a category of its own, starts working within a few minutes!) Everyone responds to insulins slightly differently.

Another major difference is that human insulins are meant to replicate the insulin found in the human body but analog insulins are genetically modified to change how insulin acts in your body, making them absorb and work faster. But they also cost more.

A July 2018 report highlighted the fact that a vial of analog insulin cost between $200 to $300, compared to $25 for human insulins. The cost of insulin analogs tripled between 2002 and 2013! 

In 2022, GoodRX lists the average list price of Fiasp (an analog insulin) at $661.44 for someone with diabetes in the U.S. Meanwhile, the website lists the average list price of a human insulin, like Humilin N, around $175 before any discounts are taken into account.

Insulin affordability

The price of insulin has been soaring for decades. Affordability is a huge problem for people with diabetes who come from all walks of life, regardless of their insurance coverage.

Companies like CivicaRX want to make affordability the standard for all people with diabetes, instead of the problem. Launching in 2024, Civica Rx aims to manufacture and distribute biosimilar rapid-acting and long-acting insulins for no more than $30 per vial and $55 per box of five pens, regardless of insurance status.

High-quality, modern insulin must be available to people with diabetes regardless of employment or insurance status, across all demographics, without barriers and at an affordable and predictable price point.

Learn more about insulin affordability and how you can become an advocate here.

WRITTEN BY Julia Flaherty, POSTED 04/14/22, UPDATED 07/27/23

Julia Flaherty is a published children’s book author, writer and editor, award-winning digital marketer, content creator and type 1 diabetes advocate. Find Julia’s first book, “Rosie Becomes a Warrior.” Julia finds therapy in building connections within the diabetes community. Being able to contribute to its progress brings her joy. She loves connecting with the diabetes communities, being creative and storytelling. You will find Julia hiking, traveling, working on her next book, or diving into a new art project in her free time. Connect with Julia on LinkedIn or Twitter.