IGF-1 Supplements vs IGF-1 Peptides: What's the Difference?

Key takeaways

• An "IGF-1 supplement" is an oral product, usually deer antler velvet, bovine colostrum, or a spray or lozenge built on them. An IGF-1 peptide such as IGF-1 LR3 is a lab-made analog sold in vials for injection. They have almost nothing in common except the name.
• IGF-1 is a protein, and swallowed protein is digested. In rats the gut destroyed IGF-1 within minutes; in 12 adults who swallowed labeled IGF-1, only fragments reached the blood.
• Colostrum raised blood IGF-1 in one small study and not in three later placebo-controlled ones. Deer antler did not change hormones in a 10-week trial, and four of six antler products tested in one lab contained human IGF-1, which the authors treated as adulteration.
• Antler and colostrum products are legal supplements if they make no drug claims; synthetic IGF-1 is not a legal supplement ingredient, and IGF-1 LR3 has no legal form at all.
• For tested athletes, IGF-1 and its analogues are prohibited at all times (WADA S2.3), and WADA has warned that oral antler products may cause a positive test.

The direct answer: an IGF-1 supplement and an IGF-1 peptide are different products. Supplements are oral, mostly deer antler velvet and colostrum, and the evidence says swallowed IGF-1 is digested before it can reach your blood intact. IGF-1 LR3, the peptide, is an injectable research analog of IGF-1 that has never been studied in humans and has no legal source. Neither is a proven way to raise IGF-1 or build muscle. Our IGF-1 LR3 profile covers the injectable side in depth, and the IGF-1 LR3 dosage page covers the numbers that circulate for it.

Supplements vs peptides at a glance

Can you absorb IGF-1 by mouth?

IGF-1 is a 70-amino-acid protein, and the digestive tract is built to take proteins apart. In adult rats, IGF-1 placed in the duodenum or ileum was degraded with a half-life of about 2 minutes; it lasted somewhat longer in the stomach and longer in the colon. The authors tested ways to protect it and found that the N-terminal extension of IGF-1 LR3 did not help, nor did binding it to IGFBP-3; an antibody against IGF-1 and dietary proteins such as the milk protein casein did slow the breakdown in gut fluids. Their conclusion was that IGF-1 cannot be expected to keep its activity if delivered orally (Xian 1995).

The human evidence points the same way. In a 2002 study, 12 adults swallowed IGF-1 labeled with a radioactive tracer. An hour later, 96% of the radioactivity in their blood was in fragments of about 0.6 kDa, a small fraction of IGF-1's size, and the authors found no labeled IGF-1 at the positions of free IGF-1 or IGF-1 bound to its binding proteins. The authors wrote that the data gave no support to the absorption of IGF-1 from colostrum (Mero 2002).

Sprays and lozenges are often marketed as getting around digestion by absorbing through the lining of the mouth. We found no published study showing that any IGF-1 spray or lozenge raises blood IGF-1 in people.

Colostrum

Colostrum, the first milk after birth, naturally contains IGF-1 and other growth factors. The studies of whether it raises blood IGF-1 disagree:

• A rise: in 2002, 19 athletes taking 20 g a day of a colostrum product during two weeks of training had a significant increase in serum IGF-1 compared with 11 on placebo (Mero 2002). The same paper's absorption test found no intact IGF-1 crossing the gut, so the rise, if real, is better explained by something other than absorbed IGF-1.
• No change: in 2020, three studies found no effect: a single 40 g dose with exercise in 16 men, 20 g a day for 4 weeks (10 per group), and 20 g a day for 12 weeks (25 on colostrum, 29 on placebo) (Davison 2020). The senior author advises a colostrum manufacturer, which the paper discloses.

On balance, colostrum at usual doses does not reliably raise blood IGF-1. Whether it does anything else useful for athletes is a separate question this page does not try to answer.

Deer antler velvet

Growing antler is one of the fastest-growing tissues in nature, which is the source of the marketing. The evidence:

• In a trial, 38 active men were randomized to deer antler velvet extract, antler powder or placebo during a 10-week strength program. All groups gained similar strength on the main measure; the powder group improved more on two isokinetic tests, which the authors cautioned may be a chance finding. There were no changes in circulating hormones, including IGF-1, in any group (Sleivert 2003).
• In the lab, an anti-doping laboratory analyzed six commercial deer antler velvet supplements and matched human IGF-1 in four of them; the authors concluded that a pharmaceutical protein was present in products sold as all-natural supplements (Cox 2013).

So an antler product either delivers too little IGF-1 to change blood levels, or it may contain an undeclared drug. Neither is a reason to buy it.

Are IGF-1 supplements legal?

Antler velvet and colostrum are ordinary supplement ingredients. What makes a product illegal is what it contains or claims:

• Synthetic IGF-1 is a drug. The Defense Department's supplement-safety program states that synthetic IGF-1 is not permitted as a dietary supplement ingredient and cannot be legally obtained without a prescription, and warns that not every product with "IGF" in its name contains IGF-1 (OPSS).
• "IGF-1 support" products can hide drugs. In a warning letter dated December 19, 2025, FDA told a company selling children's "IGF-1 Support" growth formulas that laboratory testing had found undeclared ibutamoren (MK-677), a growth hormone secretagogue excluded from the definition of a dietary supplement; FDA cited the company's claims about boosting IGF-1 and children's height as evidence of drug use and called the products unapproved new drugs (FDA 2025).
• We found no Federal Trade Commission case naming an IGF-1 product as of October 2026.

The injectable side is simpler. IGF-1 LR3 has never been approved, is in no category of FDA's compounding list, and as a protein is a biological product outside compounding, as the IGF-1 LR3 profile and our legal tracker explain. The only legal IGF-1 is mecasermin, a prescription drug for one pediatric condition.

Drug testing

IGF-1 and its analogues are listed under WADA's S2.3, growth factors and growth factor modulators, and the S2 class is prohibited at all times, in and out of competition (WADA). For supplements, the key history is from 2013:

• In February 2013, WADA said deer antler velvet spray may contain IGF-1, urged athletes to be extremely vigilant because it could lead to a positive test, and added that there can be no guarantee that IGF-1 taken orally will not affect blood levels and test results (WADA 2013).
• In April 2013, after golfer Vijay Singh admitted using deer antler spray and was sanctioned under the PGA Tour's policy without a positive test, WADA told the Tour in writing that use of the spray, known to contain small amounts of IGF-1, was not considered prohibited; the Tour dropped the case and Singh never tested positive (Sports Illustrated 2013).

The practical rule that follows: the product is not banned, the substance is. If IGF-1 or an analog shows up in a test, the source does not matter, and a supplement adulterated with human IGF-1 (Cox 2013) is exactly how that could happen.

Bottom line

An IGF-1 supplement is an oral product whose IGF-1 is mostly digested; the best human absorption test found only fragments in the blood, colostrum's effect on IGF-1 is inconsistent, and deer antler did not move hormones in its trial. Its real risks are adulteration and, for athletes, a positive test. An IGF-1 peptide such as IGF-1 LR3 is the opposite problem: a potent injectable analog with no human data and no legal source. If your goal is muscle, our muscle-growth guide ranks what has evidence, and are peptides steroids? explains how peptides, growth factors and steroids differ; if your goal is a low IGF-1, the HGH peptides guide covers the evaluation and the prescribable options.

Frequently asked questions

+−Do IGF-1 supplements work?

Not as advertised. IGF-1 is a protein, and the stomach and small intestine break it down within minutes; in the one human test of swallowed, labeled IGF-1, what reached the blood was fragments, not the hormone. Deer antler velvet did not change hormone levels in a 10-week trial, and colostrum raised blood IGF-1 in one small study but not in three later placebo-controlled studies. Any benefit people notice is not explained by IGF-1 reaching the blood.

+−Is oral IGF-1 absorbed?

There is no good evidence that intact IGF-1 is absorbed by mouth. In rats, IGF-1 placed in the duodenum or ileum was degraded with a half-life of about 2 minutes. In 12 adults given radiolabeled IGF-1 to swallow, 96% of the radioactivity in their blood an hour later was in small fragments, and no labeled IGF-1 was found free or bound to its binding proteins. Sprays and lozenges marketed for absorption through the mouth have no published absorption data.

+−Do IGF-1 pills work?

Pills and capsules face the same problem as any swallowed protein: digestion. No study shows an IGF-1 pill raising blood IGF-1 in people. Some products sold with 'IGF' in the name do not contain IGF-1 at all, and some deer antler products tested in a lab contained human IGF-1, a pharmaceutical protein that does not belong in a supplement.

+−Does deer antler velvet contain IGF-1?

Antler tissue contains IGF-1, so extracts can carry small amounts. Whether a product does depends on the product: one anti-doping laboratory matched human IGF-1 in four of six commercial antler supplements, which the authors treated as adulteration with a pharmaceutical protein. In a randomized trial of 38 active men over 10 weeks, deer antler extract or powder did not change circulating hormones, including IGF-1.

+−Does colostrum increase IGF-1?

The evidence is mixed and mostly negative. One 2002 study found serum IGF-1 rose in athletes taking 20 g of colostrum a day for two weeks, although the same authors found swallowed IGF-1 was broken down before reaching the blood. Three later placebo-controlled studies, from a single dose up to 12 weeks of 20 g a day, found no change in IGF-1. WADA still advises athletes to be cautious.

+−Are IGF-1 supplements legal?

Deer antler velvet and colostrum are sold legally as dietary supplements, provided they make no drug claims and contain no drugs. Synthetic IGF-1 is a drug and is not permitted as a dietary supplement ingredient, according to the Defense Department's supplement-safety program. FDA sent a warning letter in December 2025 to a company selling children's 'IGF-1 Support' growth formulas that contained an undeclared drug, calling them unapproved new drugs. Injectable IGF-1 LR3 has no legal form at all.

+−Will an IGF-1 supplement make me fail a drug test?

It can. IGF-1 and its analogues are prohibited at all times under WADA's S2.3, and WADA warned in 2013 that deer antler spray may contain IGF-1 and that there is no guarantee oral IGF-1 will not affect blood levels. WADA's own warning is that such products could lead to a positive test. If you are tested, avoid antler and colostrum products unless they are third-party certified for sport.

+−Is IGF-1 LR3 the same as an IGF-1 supplement?

No. IGF-1 LR3 is a modified, more potent laboratory version of IGF-1 sold in vials for injection; it bypasses digestion, acts strongly on the IGF-1 receptor in animals, has never been studied in humans and has no legal source. An IGF-1 supplement is an oral product whose IGF-1, if present at all, is mostly digested. One is an unapproved injectable drug; the other is usually an expensive way to swallow protein.

Sources

1. StudyXian CJ, Shoubridge CA, Read LC. Degradation of IGF-I in the adult rat gastrointestinal tract is limited by a specific antiserum or the dietary protein casein. J Endocrinol 1995;146:215-25. (1995)
2. StudyMero A et al. IGF-I, IgA, and IgG responses to bovine colostrum supplementation during training. J Appl Physiol 2002;93:732-9. (2002)
3. StudyDavison G et al. Oral bovine colostrum supplementation does not increase circulating insulin-like growth factor-1 concentration in healthy adults: results from short- and long-term administration studies. Eur J Nutr 2020;59:1473-9. (2020)
4. StudySleivert G et al. The effects of deer antler velvet extract or powder supplementation on aerobic power, erythropoiesis, and muscular strength and endurance characteristics. Int J Sport Nutr Exerc Metab 2003;13:251-65. (2003)
5. StudyCox HD, Eichner D. Detection of human insulin-like growth factor-1 in deer antler velvet supplements. Rapid Commun Mass Spectrom 2013;27:2170-8. (2013)
6. SourceOperation Supplement Safety (Consortium for Health and Military Performance, Uniformed Services University). IGF-1: Is it banned? Last updated March 7, 2022. (2022)
7. RegulatoryFDA. Warning letter to Agebox Inc. (MARCS-CMS 718252): iKids-Growth 'IGF-1 Support' day and night formulas containing undeclared ibutamoren mesylate are unapproved new drugs and misbranded drugs. December 19, 2025. Read October 10, 2026. (2025)
8. RegulatoryWorld Anti-Doping Agency. The Prohibited List, S2.3 Growth factors and growth factor modulators: 'Insulin-like growth factor 1 (IGF-1, mecasermin) and its analogues' (2026 List, S2 prohibited at all times). Read October 10, 2026. (2026)
9. RegulatoryWorld Anti-Doping Agency. WADA urges vigilance over deer antler velvet spray. Statement of February 5, 2013. (2013)
10. NewsPolzer T. PGA Tour drops probe of Vijay Singh's deer antler spray use (quotes WADA's written position to the Tour). Sports Illustrated, April 30, 2013. (2013)