IGF-1 LR3: This is listed first, as it is the most common and very popular variant of IGF-1 on the market and in use by bodybuilders and athletes now. It contains bio-identical IGF-1 consisting of the original 70-amino acid chain, but with an additional 13 amino acids at its N-terminus for a total of 83 amino acids. It also possesses a second modification, where an arginine is located at the 3rd position rather than the original glutamic acid. The result of these modifications is that the IGF-1 still exhibits its original activity at the IGF-1 receptor in body tissues, and has a very low binding affinity for the IGF binding proteins mentioned earlier. It also exhibits a significantly extended half-life of approximately 20 – 30 hours as opposed to IGF-1’s 12 – 15-hour half-life. All of these factors combined have demonstrated LR3 to be about three times the potency of IGF-1.
IGF-1 Side Effects
The side effect profile of IGF-1 and most users’ tolerance to it is generally well accepted according to studies and medical literature, as well as the feedback observed from bodybuilders and athletes who have used it. However, IGF-1, like anything, is not without its potential risks and side effects. The majority of IGF-1 side effects manifest themselves more in the form of long-term side effects and risks, which usually stem from long term use (and of course, dosage).
In the short term, IGF-1 can present the side-effect of hypoglycemia (low blood glucose levels) simply due to the fact that it is, as mentioned throughout this article, a nutrient shuttling/partitioning hormone. As IGF-1 increases the uptake of glucose into muscle cells (and other cell types as well) by a rapid rate, this leaves the risk of rapidly declining circulating blood plasma levels of glucose. Although this occurs at rates far below that of insulin, it is still a potential risk and side-effect. Individuals looking to use IGF-1 who are diabetic or diabetic-prone should take caution of this IGF-1 side effect. Regardless of the potential for diabetes or not, those looking to use IGF-1 should take care to monitor their blood glucose levels and signs and symptoms of hypoglycemia, and adjust their diets accordingly.
Being that IGF-1 is indeed a growth factor and a growth hormone in and of itself, it can promote tumor and cancer growth in those individuals who either have already been diagnosed with active tumors and/or cancer, as well as those who may have had a history of cancer. It is important to understand here that IGF-1 does not cause cancer. It is a very important hormone that plays important roles in the proper functioning of our heart, nervous system, and brain function among many other functions. With that being said, those who have a history of cancer or are diagnosed active cancer patients.
Acromegaly and internal organ and intestinal tissue growth is a commonly discussed IGF-1 side effect as well. This usually comes with long-term excessive use, as well as unnecessarily high dosages. Acromegaly is the excessive growth of bone tissue, usually manifesting itself noticeably in the jaw, and extremities such as the feet and hands. In order for this to occur, periods of long uninterrupted use, as well as high dosages, are required. It is advised that no IGF-1 cycle (especially IGF-1 LR3) be used for longer than 30 days at a time before a considerable break from the compound. As time on the hormone goes on, and/or as dosages increase, IGF-1 receptor sites on muscle tissue become saturated leaving any excess IGF-1 in the bloodstream to bind to other tissues (bone, internal organs, and intestinal tissue) and initiate tissue growth in those tissues. Over time, one can see why and how this can become a problem (often irreversible) with high doses and extended periods of use.