Insulin is a peptide hormone produced by beta cells in the pancreas. It regulates the metabolism of carbohydrates and fats; in addition, it stores fat to be used for energy later. When you eat, your blood sugar increases, which causes insulin to be released.

Type 1 diabetics depend on insulin because their bodies no longer produce it. Type 2 diabetics may also require insulin if they are unable to control blood glucose levels.

insulin peptide

Fig 1. Insulin Peptide

Table of Contents


Before insulin was discovered, diabetes was a feared disease that could result in death. Doctors knew that diabetes was worsened by sugar, so patients were put on strict diets. This could buy the patients a few years, but diet alone did not save them. Doctors started to figure out the pancreas was damaged in diabetic patients, and, in 1869, German Paul Langerhans discovered that within the pancreatic tissue, that produces digestive juices, were clusters of insulin producing beta cells.

In October of 1920 in Canada, a researcher named Dr. Banting had an idea to litigate the pancreatic ducts, in order to stop the flow of nourishment to the pancreas. They used the pancreas from an animal to make an extract. In 1922, the first successful diabetic patient who was a 14 year old boy, received the extract named 'insulin' from the pancreas of cow. Dr. Banting and his fellow researcher received the Nobel Prize for their discoveries.

Today, human insulin is man-made in a lab, so there is no worries with animal contamination.


Insulin is considered the most anabolic compound in existence. Bodybuilders in the 90's started using both insulin and human growth hormone together as part of their steroid stacks. This is when the monsters we know today in the professional bodybuilding world came along.

When insulin is injected, protein and other nutrients will rapidly shuttle into the muscles. This means you will be able to utilize far more protein than a normal person. For this reason, bodybuilders will use insulin before a meal to increase anabolism.

The downside is you could also store fat, some bodybuilders report putting on a lot of body fat while using insulin. They usually find this bodyfat difficult to lose. For this reason, it's advised to use insulin as part of a stack with HGH/steroids and eat clean (low-GI carbohydrate etc).

Side Effects

If insulin is abused, or used incorrectly, it can kill you or cause coma. Users may experience low blood sugar symptoms, such as sweating, blurred vision, dizziness, weakness, and anxiety. It is important for bodybuilders to keep dextrose or any sort of sugar on hand at all times and avoid falling asleep after using insulin.


There are different types of insulin, with different durations and half-life.

Humalog is the fastest insulin available, starts working in about 10minutes - peaking at around 1.5hours. However, Humulin R is also fast acting, it starts working in about 30-60 minutes - peaking at around 2-3 hours. It is available without a Rx (prescription) in the USA, so it is the most popular. Short acting insulin is safer to use because you have a shorter window where your blood sugar potentially crashes to dangerous levels. Professional bodybuilders will take 10-20iu's or more per day; a new user does not need to take this much.

The most dummy proof and safe way to take insulin is as follows:

After a workout, inject 3-4iu's of Humulin R (fast acting insulin); immediately after, take a protein shake consisting of 150g of mixed carbohydrates and 40g of protein. Then 30 minutes later eat a well balanced meal of protein, carbs, and vegetables. Monitor how you feel, if you need some juice or a candy bar, have them on hand. After 3-4 hours you are safe.


Fig 2. Humalog

As time goes on, you can gradually increase your insulin dose post-workout.

Some users will dose insulin in small amounts throughout the day before meals, and some like it pre-workout with a shake instead. It is important to always keep sugar on hand just in case you need it, and to always gradually up your dosage – never spike it.

Insulin should be stacked with human growth hormone (HGH), anabolic-androgenic steroids (AAS), and T3 for optimal results. Running it solo is not recommended.

humulin r

Fig 3. Humulin R


Insulin is a very strong peptide that has saved countless people who suffer from diabetes. Bodybuilders can use it to reach their goals and better utilize the nutrients they take in. However, it should be used with caution and only by experienced users.


Want to read about Insulin on our forums? check out these threads:


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