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Hormones & endocrine-related compounds

IGF-1

Insulin-like growth factor 1

IGF-1 is a growth-factor hormone; prescription mecasermin is recombinant human IGF-1. Compare native IGF-1, LR3/DES analogues, and oral product labels separately: they are not interchangeable. Direct IGF-1 nootropic benefit, dose, and cycle are unestablished. Mecasermin injection has documented severe hypoglycemia, including seizures.

Glucose MetabolismHormonal Axis RelatedEndogenous CompoundBioavailability SensitiveClinical ResearchInsufficient EvidenceForm Dependent Evidence
Updated October 2026/6 min read/5 citations
Reviewed by the NootropicsIndex editorial team.Method: prioritize cited human research and official safety or regulatory sources; compare retailer-listed prices without endorsing products.Affiliate disclosure
01

What is it?

What IGF-1 is

2

IGF-1 is insulin-like growth factor 1, an endogenous peptide hormone that binds IGF1R and participates in growth, glucose, and cell-signaling pathways. Mecasermin is recombinant human IGF-1 used as a prescription subcutaneous injection in narrow pediatric endocrine contexts, not a conventional nootropic supplement.

Compare identities before prices4
LR3 and DES are synthetic IGF-1 analogues, not synonyms for native IGF-1 or mecasermin. An oral product marketed with IGF-1 wording also needs its original ingredient label checked; its name alone does not establish the same molecule, absorption, or clinical effect.
02

Names, aliases and forms

Common NamesInsulin-like growth factor 1; Somatomedin-C
Spelling variantsIGF-I; IGF1
Pharmaceutical NameMecasermin
Chemical NameRecombinant human insulin-like growth factor 1
03

Mechanisms of action

Growth-factor signaling, not stimulant pharmacology

1

IGF-1 acts through the IGF-1 receptor and downstream pathways such as PI3K-AKT and Ras-MAPK. These pathways are relevant to growth and metabolism; they do not imply a focus, memory, or productivity benefit in healthy adults.

04

Potential effects and evidence map

IGF-1 biology and pediatric mecasermin treatment are distinct from evidence for healthy-adult cognitive enhancement. A cognitive trial that raised IGF-1 used tesamorelin, a different hormone analogue; it cannot validate direct IGF-1, LR3, DES, lozenges, or sprays. The references reviewed here establish no nootropic dose or benefit magnitude for those products.

Effect domainMagnitudeGrade
Memory / learning5
UnknownConfidence: Low

A memory benefit from direct IGF-1 use is unestablished for healthy adults.

Note The cited cognition trial administered tesamorelin, not IGF-1; verbal memory showed a trend and visual memory did not benefit.

0/5
E
Focus / attention5
UnknownConfidence: Low

Focus and attention benefits of direct IGF-1 products are unestablished.

Note Executive-function findings with a different hormone analogue do not establish efficacy of direct IGF-1, LR3 or DES.

0/5
E
Physical energy / endurance4
UnknownConfidence: Low

The cited analogue-detection research does not establish an endurance or recovery benefit.

Note Analytical detection is not a performance trial; this rating does not summarize all growth-hormone research.

0/5
E
Cellular / long-term brain support1
UnknownConfidence: Low

Growth-factor signaling does not establish a long-term brain-support benefit from supplementation.

Note Molecular and cellular evidence cannot quantify a healthy-adult clinical benefit.

0/5
E
05

Typical dosages and timing

Pediatric mecasermin injection20.04-0.12 mg/kg

This range spans the U.S. label starting-to-maximum amount per injection in specialist pediatric care. It is clinical context, not an established healthy-adult oral dose or an LR3/DES regimen. A vial mass is a package amount, not a validated nootropic dose.

06

Timing & effect horizon

Effect horizonUnknown
Unknown
Mecasermin half-life2Acute
5.8 hours
Clinical half-life has limited scope2

The 5.8-hour value is the mean terminal plasma The time for blood levels to fall by half during the final elimination phase.Source of subcutaneous mecasermin in pediatric severe primary IGF-1 deficiency. It does not measure cognitive onset or benefit duration and cannot be transferred to LR3, DES, lozenges, or sprays.

07

Safety, side effects and risk profile

Oral base risk cannot be quantified2
There is no established healthy-adult oral dose, duration, or sufficiently applicable safety dataset for numerical calibration here. The overall rating is therefore unknown. This does not erase the severe clinical hypoglycemia hazard of injected mecasermin or establish safety of research analogues and oral-marketed products.
Evidence uncertainty2
Confidence: High

No established healthy-adult oral dose and duration are available here for numerical base-risk calibration.

Note Unscored does not mean safe; clinical injection hazards are described separately.

Unscored
E
Legal / regulatory risk3
Confidence: High

Under the 2026 WADA rules, IGF-1, mecasermin and analogues are prohibited at all times in covered sport.

Note An eligibility restriction is separate from a physiological harm estimate.

Unscored
A
Interaction risk2
Confidence: High

Injected mecasermin can cause severe hypoglycemia, including seizures or loss of consciousness; other glucose-lowering treatment may compound this concern.

Note Clinical injection warning; incidence and magnitude cannot be transferred to oral products or research analogues.

Unscored
A
Hormonal caution2
Confidence: High

Mecasermin carries a pediatric malignancy contraindication and postmarketing neoplasia warning; causation of new cancers is unresolved.

Note Reports were concentrated in cancer-predisposed patients and above-label exposure. This is not a quantified cancer risk for healthy oral use.

Unscored
A
Pregnancy / lactation caution2
Confidence: Medium

The U.S. mecasermin label lacks pregnancy and human lactation data.

Note This evidence gap concerns a special population; it does not set the healthy-adult base score.

Unscored
A
Headache / dizziness2
Confidence: Medium

Clinical mecasermin warnings include intracranial hypertension; headache and dizziness also occurred in the pediatric trials.

Note The clinical route and pediatric disease population limit transferability to other products.

Unscored
A
Severe hypoglycemia is documented2

The mecasermin label documents severe hypoglycemia, including seizures and loss of consciousness, during pediatric injection treatment. This is an established clinical hazard even though an oral-product risk score cannot be estimated.

Malignancy warning2

The U.S. mecasermin label contraindicates treatment in pediatric patients with malignant neoplasia or a history of malignancy. Postmarketing tumors were reported, often with predisposition or above-label exposure; the label states that a causal relationship to new neoplasia is unknown.

Other labeled serious cautions2

Mecasermin injection warnings also cover anaphylaxis and intracranial hypertension. Some growth-related pediatric warnings, including hip growth-plate problems and scoliosis progression, are population-specific. The preserved drug formulation has a separate benzyl-alcohol warning for infants.

08

Interactions and cautions

Glucose-lowering medication context2

The mecasermin patient information flags insulin and other diabetes medicines. Combined glucose-lowering effects are clinically relevant, but the label provides no evidence-based supplement stack or risk estimate for oral IGF-1-marketed products.

09

Legal and regulatory status

United States prescription status2

As of October 2026, U.S. prescribing information describes Increlex (mecasermin) as a prescription subcutaneous drug for specific pediatric growth-failure indications. This approval does not establish approval or lawful sale of LR3/DES or oral products; rules for those categories and other markets require separate checks.

WADA sport status3

For athletes governed by WADA rules, the 2026 Prohibited List names insulin-like growth factor 1, mecasermin, and analogues under S2.3 growth factors, prohibited at all times. This sport rule is not a general-law statement.

10

Practical buying and quality notes

  • Check the exact molecule, original ingredient panel, amount per vial, and number of vials before comparing package prices. LR3, DES, native IGF-1, and oral-marketed products are separate comparisons. Vendor purity or testing claims do not establish clinical equivalence, sterility, or human safety.4
  • Some linked rows have generic shipping/purity copy as a title, a vial kit classified as capsules, or conflicting mass/count fields. Verify those details at the merchant before calculating total mass and cost per milligram. A displayed capsule count or normalized price is not dosing evidence or a reliable cheapest-product ranking.4
11

FAQ

Are LR3 and DES the same as mecasermin?

4

No. LR3 and DES are modified IGF-1 analogues. Mecasermin is recombinant human IGF-1 in a prescription injection. Findings, dose assumptions, and timing cannot be transferred between these identities.

Does raising IGF-1 prove a nootropic effect?

5

No. A cognition trial raised IGF-1 using tesamorelin, a growth hormone-releasing hormone analogue, rather than administering IGF-1. Its findings do not establish cognitive benefit from direct IGF-1 or the products listed here.

What dosage does an IGF-1 vial support?

2

Its label may describe the amount in the package. That amount does not establish a safe dose, frequency, or route for a person. The reviewed sources provide no validated healthy-user nootropic dosing framework.

How long do effects last, and is there a cycle?

2

A reliable healthy-user cognitive onset, effect duration, or cycle is unestablished. The clinical plasma half-life shown above is not a benefit-duration measurement or a cycle recommendation.

Is IGF-1 banned in sport?

3

For WADA-covered sport, yes. The 2026 Prohibited List includes insulin-like growth factor 1, mecasermin, and analogues under S2.3 growth factors, prohibited at all times. Athletes should not rely on vendor category labels or supplement-style packaging.

What does an unscored safety rating mean?

2

It means the evidence does not support a numeric healthy-adult oral risk estimate. It does not mean low risk: the established mecasermin injection hazards and special-population cautions remain relevant to their stated clinical context.

12

References

  1. UniProtKB. P05019 (IGF1_HUMAN): Insulin-like growth factor 1. Entry version 262, 2 September 2026. Accessed 19 October 2026.
  2. DailyMed. INCRELEX (mecasermin) injection, for subcutaneous use. U.S. prescribing information revised October 2025. Accessed 19 October 2026.
  3. World Anti-Doping Agency. The 2026 Prohibited List: International Standard. Section S2.3 lists insulin-like growth factor 1 (IGF-1, mecasermin) and analogues as prohibited at all times.
  4. Thomas A, Walpurgis K, Delahaut P, et al. Determination of LongR3-IGF-I, R3-IGF-I, Des1-3 IGF-I and their metabolites in human plasma samples by means of LC-MS. Growth Hormone & IGF Research. 2017;35:33-39.
  5. Baker LD, Barsness SM, Borson S, et al. Effects of growth hormone-releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults: results of a controlled trial. Archives of Neurology. 2012;69(11):1420-1429.
Note

This page is informational and summarizes available evidence. It is not medical advice, a recommendation, or a substitute for guidance from a qualified clinician.