IGF-1 Benefits: What Studies Report

What the literature actually covers

Insulin-like growth factor 1 (IGF-1) appears in medical literature in several unrelated contexts, and those contexts rarely overlap with the way the molecule is discussed informally. Some published work concerns replacing a deficient hormone axis in children; some concerns measuring circulating IGF-1 as a biomarker in exercise and oncology trials; some concerns blocking IGF-1 or its receptor because signalling is excessive or pathological. Reading these as one body of "benefits" produces a misleading picture.

This page organises published findings by outcome domain and labels the study type, the population studied and the direction of the reported effect. The framing throughout is "studied for" and "reported in studies" — not "works for". This page is for educational purposes only and is not medical advice; consult a licensed physician about any medical question or treatment decision.

How findings are labelled here

• Review — an author-selected synthesis of prior work; not new data.
• Systematic review — a structured search and appraisal of prior studies.
• Randomised controlled trial (RCT) — participants allocated by chance to compared conditions.
• Biomarker outcome — IGF-1 was measured in blood as an outcome, not administered.

Where a domain has no supporting paper in the verified set used for this page, that is stated rather than filled in with plausible-sounding text.

Growth and development in children

The most established clinical context for IGF-1 is the growth hormone–IGF-1 axis in paediatric growth disorders. A 2020 review in Handbook of Experimental Pharmacology addressed growth hormone and IGF-1 replacement in children and described how researchers have approached replacement in this population (PMID 31932988). That review is a synthesis rather than a new trial, and its scope is paediatric endocrine deficiency states — it is not a general-population performance or wellness literature.

Two points follow from the structure of that literature. First, the clinical question in these settings was correcting a measured deficiency in a diagnosed patient, which is a different question from supplementing an already-normal axis. Second, the review discussed replacement as a monitored medical intervention (PMID 31932988), and no dosing information from it is reproduced on this page.

Muscle, sarcopenia and exercise trials

IGF-1 is frequently discussed alongside muscle, but in the trial literature summarised here it was measured rather than given. A randomised controlled trial published in Journal of Clinical Oncology in 2018 examined aerobic and resistance exercise and reported on metabolic syndrome, sarcopenic obesity and circulating biomarkers in overweight or obese survivors of breast cancer (PMID 29356607). The intervention in the study was exercise; circulating biomarkers were among the outcomes researchers tracked, which is the typical design in this field.

A separate 2025 trial in Scientific Reports compared 12 weeks of whole-body vibration training with resistance training in older people with sarcopenia (PMID 40011687). Again, the comparison was between two training modalities in an older sarcopenic population, not between IGF-1 administration and placebo.

The practical reading is that these trials inform what training does in defined populations (PMID 29356607, PMID 40011687). They do not establish that raising IGF-1 by any external means produces the same muscle outcomes, because that was not the question either trial asked.

Cardiovascular system

A 2019 review in Current Pharmaceutical Design examined the effects of IGF-1 on the cardiovascular system (PMID 31692426). As a review, it collates experimental and clinical observations from other investigators rather than generating new human outcome data, and review-level evidence of this kind is generally treated as hypothesis-organising rather than confirmatory.

Readers searching for cardiovascular "benefits" should note the asymmetry in this field: signalling molecules that act on cardiac and vascular tissue are studied in both directions — too little and too much are each associated with described clinical pictures. The cardiovascular review sits in that context (PMID 31692426), alongside the acromegaly literature summarised further down this page, where lowering IGF-1 is the therapeutic goal (PMID 26610414).

Eye and neurovascular development

One of the more specific research settings is retinopathy of prematurity. A 2016 paper in Early Human Development discussed IGF-1 in retinopathy of prematurity framed as a central nervous system neurovascular disease (PMID 27650433). This is a neonatal population with a distinct developmental physiology, and findings there are not transferable to adults by analogy.

IGF-1 receptor signalling in thyroid eye disease

Thyroid eye disease is where the literature most clearly runs opposite to the "more IGF-1 is better" intuition. A 2015 article in Hormone and Metabolic Research reviewed medical treatment of Graves' orbitopathy (PMID 26361263), and a 2014 review in Current Opinion in Endocrinology, Diabetes, and Obesity covered immunotherapy for Graves' ophthalmopathy (PMID 25105999). Both reviews sit in a field where interrupting growth-factor receptor signalling in orbital tissue has been a central therapeutic strategy.

More recently, THRIVE was described as a phase 3, randomised, double-masked, placebo-controlled study of veligrotug for active thyroid eye disease in Ophthalmology (PMID 42223386). The design features worth noting are placebo control and double masking, which are the strongest features available in this kind of trial; the compound studied was an antagonist-class agent, not supplemental IGF-1 (PMID 42223386).

When IGF-1 is elevated: the acromegaly literature

In acromegaly, normalising an elevated IGF-1 level is a treatment target rather than an adverse outcome to be avoided. A 2016 review in Nature Reviews Endocrinology covered new therapeutic agents for acromegaly (PMID 26610414), and a 2022 Czech-language review in Vnitřní lékařství addressed pegvisomant in the treatment of acromegaly (PMID 36402555). A 2019 article in Expert Review of Endocrinology & Metabolism discussed surgical–pharmacological interactions in the treatment of acromegaly (PMID 30595057).

This cluster matters for anyone reading "IGF-1 benefits" in isolation. Across these three reviews, the clinical effort described is directed at reducing growth hormone and IGF-1 activity, not increasing it (PMID 26610414, PMID 36402555, PMID 30595057). A biological signal with a therapeutic goal of suppression in one disease state is not a signal with an open-ended dose–benefit relationship.

Skin and acne

Diet, hormones and acne are linked in the dermatology literature, and IGF-1 is one of the mechanisms commonly proposed. A 2022 systematic review in JAAD International assessed diet and acne (PMID 35373155). The exposure examined in that systematic review was dietary, and the outcome was acne — it did not test administered IGF-1, so it cannot be read as evidence either for or against an IGF-1 product affecting skin (PMID 35373155).

Outcomes commonly associated with IGF-1 that these sources did not test

Several frequently searched claims have no supporting paper in the verified set behind this page. Stating that plainly is more useful than substituting adjacent evidence.

• Fat loss or body recomposition in healthy adults — not an outcome in any source cited here.
• Anti-ageing or lifespan extension — not tested; the acromegaly literature in fact describes lowering IGF-1 as a treatment aim (PMID 26610414).
• Cognitive enhancement or mood — no cognition outcome appears in these sources.
• Tendon, ligament or wound healing in adults — not an outcome in the verified set.
• Athletic performance in healthy trained people — the exercise trials cited here studied training interventions in a breast cancer survivor population and in older adults with sarcopenia (PMID 29356607, PMID 40011687), not IGF-1 administration in athletes.
• Joint or cartilage repair — no such outcome in these sources.

Adverse Events and Safety Signals: What Studies Report

No quantified adverse-event tables are reproduced on this page, because the sources summarised here are reviews and trials whose safety detail sits outside what can be verified from the citations used. What can be said is structural. The acromegaly reviews describe a disease of excess growth hormone and IGF-1 activity in which pharmacological and surgical approaches are used to reduce that activity (PMID 30595057, PMID 36402555). The thyroid eye disease literature describes interrupting growth-factor receptor signalling as a therapeutic strategy, evaluated in a randomised, double-masked, placebo-controlled phase 3 setting (PMID 42223386, PMID 26361263).

Taken together, those two strands indicate that IGF-1 signalling is studied as a two-sided variable with disease states at both ends — a reason safety questions in this area are handled by clinicians with laboratory monitoring rather than estimated from general reading.

Summary table of reported domains

How a careful reader can weigh this

1. Check whether IGF-1 was administered or merely measured; most exercise work measures it (PMID 29356607).
2. Check the population — neonates, children with deficiency, older adults with sarcopenia and acromegaly patients are not interchangeable (PMID 27650433, PMID 31932988).
3. Check the direction — several of these literatures describe reducing, not raising, IGF-1 activity (PMID 26610414).
4. Check the design — a placebo-controlled, double-masked phase 3 trial carries different weight from a narrative review (PMID 42223386, PMID 31692426).

Background on the molecule itself is covered in the IGF-1 overview.

References

• GH and IGF-1 Replacement in Children (Handbook of Experimental Pharmacology, 2020)
• Effects of 12-week whole-body vibration training versus resistance training in older people with sarcopenia (Scientific Reports, 2025)
• Effects of Aerobic and Resistance Exercise on Metabolic Syndrome, Sarcopenic Obesity, and Circulating Biomarkers in Overweight or Obese Survivors of Breast Cancer: A Randomized Controlled Trial (Journal of Clinical Oncology, 2018)
• Effects of IGF-1 on the Cardiovascular System (Current Pharmaceutical Design, 2019)
• IGF-1 in retinopathy of prematurity, a CNS neurovascular disease (Early Human Development, 2016)
• THRIVE: A Phase 3, Randomized, Double-Masked, Placebo-Controlled Study of Veligrotug for Active Thyroid Eye Disease (Ophthalmology, 2026)
• Medical Treatment of Graves' Orbitopathy (Hormone and Metabolic Research, 2015)
• Immunotherapy for Graves' ophthalmopathy (Current Opinion in Endocrinology, Diabetes, and Obesity, 2014)
• New therapeutic agents for acromegaly (Nature Reviews Endocrinology, 2016)
• [Pegvisomant in the treatment of acromegaly] (Vnitřní lékařství, 2022)
• Surgical-pharmacological interactions in the treatment of acromegaly (Expert Review of Endocrinology & Metabolism, 2019)
• Diet and acne: A systematic review (JAAD International, 2022)