Peptides  /  IGF-1 LR3
For Adults · Compounded Peptide

IGF-1 LR3

A long-acting IGF-1 analog.

A modified form of insulin-like growth factor 1, engineered to bind less to its carrier proteins. Prescribed online after a licensed provider reviews your online visit, compounded by U.S. 503A pharmacies, and shipped discreetly to most U.S. states.

$299

Start your online visit →

A few private questions, then a licensed provider reviews your answers.

100% Online 503A Compounded Licensed Providers Discreet Shipping
ForbiddenRx IGF-1 LR3 vial
At a glance
Form
Injection
Cadence
Set by your provider
Class
Insulin-like growth factor analog
Guided by
Provider review
Helps with
Growth & recovery category
For
Adults 18+
The basics

What is IGF-1 LR3?

What it is
Insulin-like growth factor analog
Forms
Injection
Supplied as
Strength set by your prescriber
Dosing
Set by your prescriber
Supply
1-month
Visit
Online, reviewed by a licensed provider
Prescription
Provider-reviewed · not available OTC
Shipping
Discreet, unmarked · most U.S. states
Start your online visit →

IGF-1 LR3 (Long R3 IGF-1) is a modified form of insulin-like growth factor 1, an 83-amino-acid analog with an arginine substitution at position 3 and a 13-amino-acid N-terminal extension. The changes reduce its binding to IGF-binding proteins, which lengthens its activity.

IGF-1 LR3 is used widely in cell-culture research. It is not an FDA-approved medication, and there is little published research on it in humans. The preparation dispensed here is compounded.

This is a compounded preparation, not an FDA-approved medication, and compounded drugs are not reviewed by the FDA for safety or effectiveness. Individual results are not guaranteed. It is prescribed only where a licensed provider determines it is appropriate after reviewing your health history.

Why people ask about it

Why does IGF-1 LR3 come up?

IGF-1 LR3 appears in recovery conversations because IGF-1 is the main mediator of growth hormone's effects. The modified form is a laboratory tool, and there is little published human research on it.

✔A provider decides, not a quiz

Every IGF-1 LR3 prescription here follows a review by a licensed provider of your health history, current medications and goals. If it isn't appropriate for you, it isn't prescribed.

✔Compounded, not a research chemical

Your vial is compounded by a licensed U.S. 503A pharmacy and dispensed against a prescription written in your name — not sold as a "research only" product with no oversight.

Know the difference

Prescribed IGF-1 LR3 vs. supplements and grey-market vials — what's the difference?

The short answer: unregulated supplements make claims nobody checks, "research only" vials sold online carry no prescription, no pharmacy and no accountability, and a prescribed IGF-1 LR3 is compounded by a licensed 503A pharmacy against a provider's order written for you.

 Oral supplement"Research only" vialPrescribed IGF-1 LR3 (Rx)
What it isAn unregulated oral precursorA vial sold without a prescriptionCompounded IGF-1 LR3 dispensed on a provider's order
Licensed provider reviews youNoNoYes — before anything is dispensed
Compounded by a licensed pharmacyNoNoYes — U.S. 503A
Your name on the vialNoNoYes
Dose set by a prescriberNoNoYes
Legal to sell for human useAs a supplementNoYes — by prescription

The simplest test of any peptide seller: is your name on the vial? A "research only" label means no prescriber reviewed you, no licensed pharmacy compounded it, and nobody is accountable for what is actually inside.

How it works

How does getting IGF-1 LR3 actually work?

Three steps: answer a short set of medical questions, a licensed provider reviews them, and if they prescribe, a 503A pharmacy compounds and ships it.

I

Answer a few questions

A short private medical questionnaire — your history, current medications and what you are hoping to address. It takes a couple of minutes.

II

Meet your provider live

A provider licensed in your state reviews your answers online — no appointment, no waiting room. They decide whether IGF-1 LR3 is appropriate.

III

Compounded & shipped

If they prescribe, a licensed U.S. 503A pharmacy compounds your vial and ships it discreetly, with your name on the label.

Who it's for

Who is IGF-1 LR3 for?

It's for adults who want IGF-1 LR3 prescribed and compounded properly rather than bought from a grey market. Whether it is appropriate for you is a decision for the provider who reviews your visit.

✔Interested in the growth-factor category

You have read about IGF-1 LR3 and want it prescribed properly rather than bought from a grey market.

✔You want a real prescription

Reviewed by a licensed provider, compounded by a 503A pharmacy, dispensed with your name on the vial.

✔You want the dosing decided for you

The amount and schedule are set by your prescriber, not selected here or taken from a forum protocol.

✔You are open to a provider review of your history

Growth factors are not appropriate for everyone, including people with an active cancer or diabetes.

✕When it's not the right fit

IGF-1 LR3 is mainly a laboratory reagent with little published human data. IGF-1 activity can lower blood sugar; tell your provider about diabetes, any cancer history or diabetes medication. It is a compounded preparation, not an FDA-approved medication, and compounded drugs are not reviewed by the FDA for safety or effectiveness. Individual results are not guaranteed. If you are pregnant or breastfeeding, have an active cancer diagnosis, or have significant kidney or liver disease, tell your provider in your answers. New or unexplained symptoms should be evaluated by a clinician rather than self-treated.

How to get it

How do I get IGF-1 LR3 online?

You answer a few questions, a licensed provider reviews your answers, and — if they prescribe — your medication is compounded and shipped to your door. No insurance required, no in-person appointment, no waiting room.

A few questions

Answer a short set of private medical questions. Add as many peptides as you like; one checkout, and a provider reviews each.

Online provider review

A provider licensed in your state reviews your answers online. Approval is never guaranteed.

Discreet delivery

If prescribed, your vial is compounded by a 503A pharmacy and ships in plain, unmarked packaging to most U.S. states.

Pricing is shown at checkout — no insurance needed, no hidden fees.

Using it & safety

How is it taken, and is it safe?

IGF-1 LR3 is compounded as injection. The amount and the schedule are set by the provider who reviews your visit — we deliberately do not publish a dosing regimen here, because that is a clinical decision about you, not a product specification.

Forms & how it's taken

Injection
Compounded as injection.
Supplied as
Strength set by your prescriber.
Dose & schedule
Set by your prescriber. Follow the directions on your label.
Supply
1-month supply.
InjectionProvider-set

Safety & side effects

⚠ Limited human research

IGF-1 LR3 is mainly a laboratory reagent with little published human data. IGF-1 activity can lower blood sugar; tell your provider about diabetes, any cancer history or diabetes medication. It is a compounded preparation, not an FDA-approved medication, and compounded drugs are not reviewed by the FDA for safety or effectiveness. Individual results are not guaranteed.

Reported effects are most often related to the injection itself or to infusing too quickly. They can include:

  • Redness, swelling or soreness at the injection site
  • Headache
  • Nausea
  • Fatigue
  • Low blood sugar
  • Joint or muscle aches

Tell your provider about every condition and medication before starting, including pregnancy or breastfeeding. Stop and seek care for signs of an allergic reaction — rash, swelling of the face or throat, or difficulty breathing. For emergencies call 911.

Compare your options

Which longevity peptide fits you?

A side-by-side look at the gh / longevity options available through ForbiddenRx. Which one is appropriate for you is decided by the provider who reviews your visit.

TreatmentWhat it isFocusFormForRx required
IGF-1 LR3
This page		Insulin-like growth factor analogGrowth & recovery categoryInjectionAdults 18+Yes
5-Amino-1MQSmall-molecule NNMT inhibitor (oral)Metabolic categoryCapsulesAdults 18+Yes
AOD-9604Growth-hormone fragment (hGH 176-191)Metabolic categoryInjectionAdults 18+Yes
CartalaxSynthetic tripeptideLongevity categoryInjectionAdults 18+Yes
Questions, answered

IGF-1 LR3 FAQ

What is IGF-1 LR3?

It is a modified, longer-acting form of insulin-like growth factor 1, engineered to bind less to the proteins that normally carry IGF-1 in the blood.

Is it the same as the FDA-approved IGF-1 product?

No. An FDA-approved recombinant IGF-1 (mecasermin) exists for a specific growth disorder. IGF-1 LR3 is a different, modified molecule and is not FDA-approved. It is a compounded preparation, not an FDA-approved medication, and compounded drugs are not reviewed by the FDA for safety or effectiveness. Individual results are not guaranteed.

Can it affect blood sugar?

Yes. IGF-1 activity can lower blood sugar. Tell your provider about diabetes or any glucose-lowering medication.

Do I have to book an appointment?

No. You complete the questionnaire online and a licensed provider reviews it — there is no scheduling step and no waiting room.

Can I order more than one peptide?

Yes. Add each one to your cart and check out once. A provider reviews every treatment in your order.

Credibility you can verify

Care held to a higher standard

Licensed Providers

U.S. board-certified clinicians

503A Pharmacies

U.S.-based compounding partners

Most U.S. States

We confirm your state during intake

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Category

The Peptide Catalog

Every peptide we can dispense, each prescribed by a licensed provider and compounded by a 503A pharmacy.

Learn more →

Start with a real prescription

If you are going to take IGF-1 LR3, take one a licensed provider prescribed and a 503A pharmacy compounded with your name on it. Answer a few questions and a licensed provider reviews them.

Start your online visit →

  • Discreet, unmarked packaging
  • Refills so you never miss a dose
  • Labs guiding every adjustment
  • Licensed providers in most U.S. states
Medically reviewed

Sources & references

Medically reviewed by ForbiddenRx Medical Affairs — Independent, licensed medical providers · Last reviewed August 2026. This page was written and is periodically reviewed for medical accuracy in line with clinical guidance followed by the independent, licensed medical providers in the ForbiddenRx network. It is provided for general educational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Always talk with a licensed provider about your individual health.

  1. PubMed — Long R3 IGF-I, published literature.
  2. PubMed — IGF-I analogs and binding-protein affinity, published studies.
  3. U.S. Food & Drug Administration. 503A Pharmacy Compounding — the regulatory basis for how this preparation is dispensed.
For further reading

Clinical references

This page is educational and is not medical advice.