IGF-1 is a peptide consisting of 70 amino acids with a molecular weight of 7649 Da. IGF-1 has an A and B chain connected by disulfide bonds, like insulin, which is how it gets its name. The structural similarity to insulin explains the ability of IGF-1 to bind (with low affinity) to the insulin receptor. IGF-1 is secreted by many tissues and the secretory site seems to determine its actions. Most IGF-1
is secreted by the liver and is transported to other tissues, acting as an endocrine hormone. IGF-1 is also secreted by other tissues, including cartilaginous cells, and acts locally as a paracrine hormone.
Most of the IGF-1 produced by the liver is secreted for its proliferative and growth effects. Lower IGF-1 and growth hormone are often associated with excess body fat. IGF-1 and other proteins in the IGF family are growth factors that stimulate the proliferation and survival of various cell types including muscle, bone, and cartilage tissue. IGF-1 plays an important role in childhood growth and continues to have anabolic effects in adults. A synthetic analog of IGF-1, mecasermin is commercially available and is used for the treatment of growth failure. Therapeutic administration of IGF-1 is associated with reversing insulin sensitivity, reducing weight and increasing metabolic expenditure as well as potential reversal of degeneration of spinal cord motor neuron axons in certain peripheral neuropathies.
IGF-1 LR3 has a modified amino acid sequence compared to biological IGF-1. It has an additionally arginine at amino acid position 2. By making this change, it gives the molecule higher potency and a much longer half-life. For this reason, it is commonly used as long-acting version for the same therapeutic reasons as the IGF-1.


Effects of human growth hormone, insulin-like growth factor I, and diet and exercise on body composition of obese postmenopausal women.
To determine the effects of GH and insulin-like growth factor I (IGF-I) administration, diet, and exercise on weight loss, body composition, basal metabolic rate (BMR), muscle strength, and psychological status, 33 moderately obese postmenopausal women (67.1 +/- 5.2 yr) participated in a 12-week randomized, double-blind study. Participants were placed on a diet that provided 500 Cal/ day less than that needed for weight maintenance, and they walked 3 days and strength trained 2 days each week. Subjects also self-injected GH (0.025 mg/kg, IGF-I (0.015 mg/kg, a combination of these doses of GH and IGF-I, or placebo (P). Twenty-eight women completed the study, as ve subjects dropped out due to
intolerable side-effects (e.g. edema). Weight loss occurred in all groups, with the largest decrease occurring in the GH plus IGF-I group (5.6 +/- 1.4 kg). Fat mass significantly decreased in all groups, with the largest losses observed in GH and GH plus IGF-I groups (6.3 +/- 1.8 and 8.4 +/- 2.8 kg, respectively). Despite weight loss, BMR was maintained in all groups. Muscle strength increased with training for all groups, and depression and anxiety scores decreased in groups receiving IGF-I. These data show that obese postmenopausal women can lose weight and fat without compromising fat-free mass, BMR, or gains in muscle strength and that GH and IGF-I given together may enhance fat loss over either given alone.

Contact us and discover
your new normal.

  • MM slash DD slash YYYY
  • :
    Tuesday – Saturday: 10am-6pm
    Sunday – Monday: Closed

Contact us today to
schedule your consult!

Hormone Replacement Therapy

Take the guesswork out of balancing your hormones.

Custom plans at $179/mo

Thyroid Disorder Treatment

Reverse the effects of an age-related thyroid disorder.

Custom plans at $129/mo

Have more questions?

Contact us for a no-obligation consultation. Talk to a VitaHealth expert today.


Leave a Reply

Your email address will not be published. Required fields are marked *

Fill out this field
Fill out this field
Please enter a valid email address.