Insulin-like Growth Factor 1 (IGF-1), also known as Somatomedin C, is a peptide related to insulin that helps encourage normal bone and muscle growth and helps decrease blood glucose levels. Bodybuilders have known for years that IGF-1 helps cells to burn fat and increase lean body mass. In fact, this peptide can accelerate weight gain attributed to an increase in muscle mass while keeping the fat off. It can improve energy during a workout and help recovery time after one. So how does this work? IGF-1 has been found to increase in the body after resistance exercise (Jiang, et al, 2020), and increase the creation of lean muscle mass. This effect has been well documented in a number of other studies, among average adults, athletes, and the elderly. In addition, those who have received IGF-1 injections can see an increase in lean muscle mass if exercise is also engaged in. IGF-1 is triggered by Human Growth Hormone, and as such, you see a spike in IGF-1 production during late childhood and adolescence, followed by a gradual decline over the course of your life, with IGF-1 levels getting quite low among the elderly. If exercise, especially resistance exercise, is continued a pattern tends to emerge of an initial spike in IGF-1 levels as exercise commences, and then a gradual decrease as muscles grow and the IGF-1 is absorbed in the process. Extreme exercise, like that performed by athletes, may cause IGF-1 to be elevated over a longer period of time so that muscle mass increase is steady (Veloso, 2009). In the elderly, as well, resistance exercise tends to raise IGF-1 and keep it elevated, at least a bit, over time (Jiang, et al, 2019, cited above).
So what level of IGF-1 should we maintain? IGF-1 is critical for a number of reasons to the body. Extremely low levels of IGF-1 (some of which can result from genetic conditions) result in various growth disorders, including forms of dwarfism and acromegaly. Clearly, it makes sense that if Human Growth Hormone’s actions are impaired, you are likely to have problems in the development of the body. Also, since IGF-1 levels are linked to cognitive function (Aleman, et al, 2009), both by growing new brain cells and protecting existing ones, somewhat higher levels of IGF-1 are desirable to help maintain a healthy brain and to prevent cognitive decline. In this sense, IGF-1 could be thought of as having anti-aging effects. IGF-1 also helps create protein synthesis, which helps us recover more quickly from injuries (and possibly decreases recovery time from workouts). So it sounds like we should just pump up the IGF-1, right? Well, not so fast. Sustained, high levels of IGF-1 have been correlated with an increased risk of various cancers (King, et al, 2012). When you think about it, it’s easy to realize why high levels of Human Growth Hormone and IGF-1 might encourage the growth of cancer cells along with normal human cells- you are in effect engaging in a long-term supercharging of your body. You might have wondered how super healthy extreme athletes could possibly end up with cancers- one possible explanation is that they are pushing beyond the redline for extended periods of time with the amount of IGF-1 in their bodies. I’ve just said the “c” word- should that scare you off from IGF-1? Not at all- let’s take a look.
To say that you should shy completely away from IGF-1 is tantamount to saying that you shouldn’t engage in any sustained strenuous exercise either. We’ve shown how IGF-1 declines with age, how it’s necessary for maintaining and building lean muscles at the expense of fat, and for brain health and helping to prevent cognitive decline. Let’s first say that as we age, declining cognition, excess fat, lack of exercise, and wasting of muscles are far more likely to cause negative health consequences and even mortality than is an excess of IGF-1, especially if that excess is slight. Secondly, remember that as long as your exercise is not excessive, then the increase of the IGF-1 you produce will be absorbed as you build new, lean muscle mass. The key is moderation.
Unless you are an extreme athlete, you are unlikely to have any problems from excessive IGF-1 levels over an extended period of time. If you are an extreme athlete or professional bodybuilder, then there are still things you can do to minimize risk. Both normal healthy adults and athletes will benefit from cycling their exercise regimen between bulking up and leaning out. A diet lower in carbs and sugars, even a ketogenic diet may help to regulate the uptake of sugar, and therefore insulin (remember that IGF-1 functions as an insulin analog). Beyond this, a high protein, higher fat, low carb diet will provide more protein for the building of lean muscle mass, less fat, and in the process absorb more IGF-1 into the body. IGF-1, especially as an injectable peptide, should be seen as a way to kickstart your muscle building, not as a crutch to give you instant muscles. Starting with a course of IGF-1 injections, coupled with resistance exercises, you should start seeing real lean muscle acquisition fairly quickly. It’s important to exercise as well to put the IGF-1 to work instead of just accumulating in your body. If you are much older and are worried about cognitive decline or just the wasting of muscles, you still exercise, but you’ll probably find that you maintain or grow muscle more easily than you thought, and since your IGF-1 is likely to be lower, then the boost from an injectable should be noticeable. If you are younger, then start with one regimen of the IGF-1 and exercise, followed by normal or lighter exercise, and then another regimen of IGF-1 and exercise. It’s best not to stay on the compound consistently, especially long term- it’s better to treat it as a jumpstart to more lean muscle mass and less fat. Remember, as you grow muscles in that initial burst, it will be easier to maintain consistent exercise afterward.
In addition to IGF-1, you might consider boosting antioxidants and adaptogens like Alpha Lipoic Acid, Glutathione, Broccoli extract, green tea, curcumin, and Ashwagandha. All of these natural substances have numerous studies that support their antioxidant and/or adaptogenic effects, meaning they can help to eliminate the free radicals that can sometimes contribute to cancer. If you are looking to quickly jump-start the building of lean muscle, or are worried about the muscular wasting, fat accumulation, and cognitive decline that comes with aging, then IGF-1 therapy might be right for you. If you have difficulty in building muscle mass because of an autoimmune disease like MS, studies have also demonstrated the ability of IGF-1 to help with cognitive impairment and fatigue- IGF-1 therapy might have the ability to help you start exercising, although more study is needed. Peptide therapy can be an amazing way to stimulate the body’s own pathways to improve health and anti-aging. Benefits of IGF-1 therapy can include: