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What Peptides Do Bodybuilders Use?


    Dietary supplements, including peptides, are often part of the journey to success of bodybuilders. So, the question that is commonly asked is: What peptides do bodybuilders use?

    Growth Hormone Releasing Hormones (GHRH), Growth Hormone Releasing Peptides (GHRP), and Insulin-Like Growth Factor (IGF)-I are the top peptides used in bodybuilding. It’s important to note that all peptides are illegal in bodybuilding as their safety is not yet clear. Peptides can help with muscle growth, but there’s too little research for them to be legally safe.

    Read on to know what peptides are and the individual definitions of the peptides commonly used by bodybuilders. The effects of peptides on the human body will also be discussed, as well as their legality.

    What are peptides, and how do they work?

    Peptides are short chains of amino acids joined together by a bond. The chain usually comprises 50 amino acids (not enough to be protein).

    Essentially, they are the building blocks that create protein. These compounds exist in our bodies naturally and are produced naturally. But we can consume them through food, and they are synthesized artificially.

    Peptides are very useful in efficiently producing hormones, especially growth hormones.

    The primary reason bodybuilders use peptides is how they improve growth hormone production. Human Growth Hormone (HGH) helps massively in improving lean muscle mass. Our bodies use peptides to increase the secretion of HGH.

    To put it simply – peptides make it easier for the person using them to increase their muscle mass.

    Their usage may also increase strength, and some studies have found that peptides could boost testosterone production.

    Another reason bodybuilders use peptides is that they shorten the recovery period. Everyone should know that rest is as important as working out.

    Our muscles grow by slightly tearing them and then re-growing muscle fiber at the place of the tear. This makes them stronger than they were before.

    The issue about this is that it’s a slow, slow process. By rule, you shouldn’t use a muscle until it’s rested and recovered properly – and for bodybuilders, that means a lot of valuable time goes to waste. Sometimes days can pass before they can use a muscle again.

    Peptides help in delivering oxygen to muscle cells, helping them recover faster.

    Another benefit is the improved level of endurance. That’s why it’s popular among athletes other than bodybuilders.

    The types of peptides bodybuilders use

    Bodybuilder drinks protein

    Growth hormone releasing hormones (GHRH)

    These peptides help in the stimulation of growth hormone secretion.

    The duration of induced secretion will depend on the specific type of peptide that you use.

    It’s important to know that these substances have their limit, and after passing them, they become ineffective.

    Some peptides that fall under the GHRH category are MOD-GRF (1-29), CJC 1295 DAC, HGH Fragment 176-191, and Sermorelin.

    Modified GRF (1-29)

    This peptide is known to be beneficial in promoting muscle growth and in helping in burning fat.

    This peptide may also be useful to those looking to slow down their aging. Some users have also reported that it helped them sleep better.

    CJC 1295 DAC

    This is the opposite of MOD-GRF (1-29). The biggest difference between the two is the length of the effect, with the half-life of this peptide being about a week long.

    The half-life of MOD-GRF (1-29) is about half an hour. This makes CJC 1925 DAC ideal for those who want to escape the stress of using peptides frequently.

    HGH Fragment 176-191

    This peptide is a fragment of the human growth hormone. Bodybuilders mainly use this before competitions when they have to minimize their fat percentage.

    This peptide is very useful in promoting fat loss and making muscle growth more noticeable.

    This is considered much more potent and useful than regular growth hormones. Another positive experience you can get out of this peptide is its anti-aging benefits.


    This peptide is commonly used for anti-aging purposes, especially by middle-aged bodybuilders. However, it’s also considered to be useful for building muscle.

    29 out of 44 amino acids that make up the growth hormone can be found in this peptide. So, it’s considered to be very potent in improving HGH levels.

    Growth hormone releasing peptides (GHRP)

    Considered an upgraded version of the GHRH, they cause an even greater growth hormone secretion in the human body.

    A big advantage these have before GHRH is that you don’t have to aim to use them at specific times when your body produces pulses.

    Growth hormone-releasing peptides will start a burst of growth hormone production virtually any time you take them.


    This peptide is very potent, and it’s used for three important purposes: anti-aging, muscle building, and fat loss.

    Users have reported that it also helps massively with fighting inflammation, and it boosts recovery, shortening the time span before they can exercise again.

    It’s believed that some professional bodybuilders use it in combination with steroids for maximum potency.

    The reason for this peptide’s potency lies in its two activities. The peptide stimulates the pituitary gland to produce more HGH, and it simultaneously suppresses Somatostatin, a hormone impeding the release of HGH.


    This peptide is considered to be the improved version of the aforementioned GHRP-6. The reason is the lack of the intense appetite boost that comes after the intake of GHRP-6.

    That’s why people looking to build lean, clean muscle mass may find it more interesting in comparison to GHRP-6.

    This peptide does not desensitize the user after being taken in low doses without breaks in between.


    This peptide is a favorite for some users. It’s very similar to GHRP-6, as it stimulates the pituitary while simultaneously suppressing Somatostatin.

    The difference is that this peptide won’t cause your appetite to surge drastically, and it won’t cause your prolactin and cortisol levels to rise.


    Neither GHRP-6 nor GHRP-2 help in secretion and subsequent release of HGH as much as this peptide does.

    Users experience an even greater release of HGH from this peptide as it’s useful for muscle building, fat loss, and anti-aging simultaneously.

    This peptide is stronger than virtually all other growth hormones releasing peptides. However, this means that it has a higher potential to desensitize the user, regardless of dosage or possible breaks in between.

    Insulin-like growth factor (IGF)-I

    This class of peptides enhances the insulin-like growth of muscles by bodybuilders. This is very useful for users looking to target specific muscle groups.

    This has become one of the more popular peptides used for muscle building over the last decade. Dorian Yates, Mr. Olympia for six years in a row in the 90s, is thought to have been a devoted user.

    This has contributed to the collective decision of many professional bodybuilders to incorporate it into their regimen. This peptide comes in different types as well.

    IGF-1 LR3

    This peptide is the most popular variant of IGF-1 peptides, and it’s available on the market today.

    It comprises 83 amino acids, adding another 13 amino acids to the sequence of standard insulin-like growth factor-1.

    It’s considered more powerful than normal IGF-1 as it has a half-life of up to 30 hours, while the regular IGF-1 only has 15 hours.

    This peptide is also commonly used to burn fat, shorten recovery periods, and slow down aging.

    Mechano growth factor (with PEG)

    This peptide is not only promoting muscle growth but also initiating the formation of new muscle cells, a study reveals.

    Its half-life length increased from minutes to days, and it’s ideal for post-workout use because it’s activated by mechanical stimulus. This peptide also helps with a quicker recovery time.

    What peptide is best for muscle growth?

    Now that we’ve defined what each peptide does, let’s divide them by use! You’ve certainly learned by now that peptides can have a massive effect on both fat loss and muscle growth.

    However, there are numerous peptides to choose from, making it difficult to single out just one and declare it ‘the best peptide for muscle growth”.

    Here’s a list of a few that we consider the best for this purpose, with explanations as to why.

    GHRP – GHRP-6

    Growth hormone releasing peptide is widely considered (by bodybuilders) and has been found to be the most effective GHRP on the market. It’s been of great use to bodybuilders who have experienced issues in meeting their high-calorie count.

    This peptide is the first component of the growth hormone secretagogues (GHS) and stimulates your appetite – about half an hour after taking it is usually the time when the user starts starving.

    This growth hormone releasing peptide increases appetite, enhances energy levels, improves muscle and strength gains significantly, increases lean body mass, improves sleep quality, shortens recovery time.


    This peptide decreases body fat, increases lean muscle mass, improves recovery. It has virtually no impact on cortisol levels and has noticeable anti-aging properties.


    This peptide increases cell regeneration and reproduction within the muscles, and it also helps increase bone density (potentially reducing the risk of osteoporosis and other issues related to the skeleton).

    It helps excellently with muscle growth and strength gain. It causes an overall improvement in performance, lowers body fat levels, and increases healing properties.

    CJC-1295 DAC

    This peptide works similarly to all the others, and if you want to know more, feel free to scroll up to the section dedicated to this peptide.

    Its effects are: shorter muscle recovery time, improved muscle definition, increased muscle mass and strength, enhanced fat metabolism, reduced body fat levels, reduced signs of aging, improved sleep quality.

    The best peptides for muscle growth

    1. Extra Large Grass-Fed Collagen Peptides

    Extra Large Grass-Fed Collagen Peptides

    Brand: Zen Principle

    Form: Powder

    Material Feature: Not Available

    Extra Large Grass-Fed Collagen Peptides 3 lb. Custom Anti-Aging Hydrolyzed Protein Powder for Healthy Hair, Skin, Joints & Nails. Paleo and Keto Friendly, GMO and Gluten Free, Pasture-Raised Bovine.
    1,215 Reviews
    Extra Large Grass-Fed Collagen Peptides 3 lb. Custom Anti-Aging Hydrolyzed Protein Powder for Healthy Hair, Skin, Joints & Nails. Paleo and Keto Friendly, GMO and Gluten Free, Pasture-Raised Bovine.
    • ENJOY THE BEST QUALITY AND VALUE compared to other brands. Our grass-fed collagen is free of hormones, GMO and antibiotics. FREE SCOOP included!
    • SUPERIOR CUSTOM FORMULA. Using leading edge research and manufacturing techniques, we created a proprietary collagen peptide blend packed with pure type 1 and 3 collagen and essential amino acids, which easily dissolves in cold or warm liquids.

    This peptide supplement by the Zen Principle Store is grass-fed and free of hormones, GMOs, and antibiotics. It is a peptide blend that contains pure type 1 and 3 collagen and essential amino acids. Since it is in powder form, it is easily dissolved in cold or warm liquids. It can be used to boost your metabolism and energy levels and also helps with muscle development. It burns more calories than fat.

    2. Vital Proteins Collagen Peptides

    Vital Proteins Collagen Peptides

    Brand: Vital Proteins

    Form: Powder

    Material Feature: Dairy Free

    Vital Proteins Collagen Peptides Powder Supplement (Type I, III) for Skin Hair Nail Joint - Hydrolyzed Collagen - Non-GMO - Dairy and Gluten Free - 20g per Serving - Unflavored 9.33 oz Canister
    • Collagen helps to restore the skin’s moisture, improving the elasticity, tone and vibrancy that’s already within you. Collagen stimulates cells that boost the production of new collagen to support healthy skin and nails.**
    • Collagen Peptides Powder ---- Sourced from grass-fed, pasture-raised bovine to ensure high quality and sustainable source of this powerful ingredient. Digested and absorbed by the body quickly for maximum benefits. Hyaluronic acid — a clear, lubricating substance found throughout the body — helps support skin hydration and elasticity.** Ingredient found in our Original Collagen Peptides.

    This peptide supplement by Vital Proteins is nutrient-dense and offers 20 grams of collagen per serving. There is no sugar, and it helps support hair, skin, nails, bones, and joints. You can mix it into your favorite hot or cold beverages, and it is gluten and dairy-free. It also supports the immune system, promotes collagen production, and promotes hydrated skin and a glowing complexion. These peptides can also be used for muscle growth and work together with Vitamin C and hyaluronic acid to support healthy ligaments, tendons, and joints.

    3. Amazon Brand – Revly Collagen Peptides

    Amazon Brand - Revly Collagen Peptides


    Form: Tablet

    Material Feature: Gluten Free

    Amazon Brand - Revly Collagen Peptides + Vitamin C, 2500 mg Collagen Peptides per Serving, 90 Tablets, 1 Month Supply
    • A blend of 2500 mg collagen peptides and 60 mg vitamin C
    • Contains Type I and III collagen (bovine).

    This peptide supplement by Amazon is a blend of 2500 mg collagen peptides and 60 mg vitamin C. It is in tablet form, so it should be taken three times daily.

    4. Collagen Peptides Powder – Hydrolyzed

    Extra Large Grass-Fed Collagen Peptides

    Brand: Sports Research Store

    Form: Powder

    Material Feature: Non-GMO, certified keto-friendly, and gluten-free

    This collagen peptide supplement contains peptides sourced from grass-fed bovine and has been hydrolyzed for better absorption. Each scoop contains 18 amino acids, including hydroxyproline, proline, and glycine.

    Collagen Peptides Powder | Hydrolyzed for Better Collagen Absorption | Non-GMO Verified, Certified Keto Friendly and Gluten Free - Unflavored
    • 1 Single Ingredient | Contains ONLY Collagen Peptides sourced from grass-fed bovine hide & Hydrolyzed for easy Absorption.
    • Highest Collagen Per Scoop | Unlike other brands, we provide 11grams of Collagen per Scoop.

    Are peptides illegal?

    Yes, peptides are illegal, and rightfully so. As with any story, this one also has two sides.

    It’s legal to use peptides for research, but research only.

    Sellers of this product getaway by a technicality. On the bottle packaging, they include a disclaimer stating that it’s illegal to use peptides for any purpose other than research.

    You can be arrested and prosecuted if you’re caught using peptides.

    A lot of testing is yet to be done before appropriate institutions approve it for public use.

    Many countries, most notably Australia, have noted a disturbing increase of recorded and suspected peptide use by athletes. This means that we might be witnessing a problem arising.

    Peptides are hot topics because there are no notable bad side effects on the people who use them.

    It’s staggering to see how many people chat in online forums about the casual use of an illegal substance and exchange experiences and advice.

    Peptides have become commonly accepted under a low profile, and people see less and less purpose in their illegality.

    Unlike steroids, the side effects of peptides aren’t as nearly as dangerous, which has caused people to widely accept them as if they were legal.

    As the author of this article, I would like to stress that I do not condone any illegal activity, especially the illegal usage of opiates or other restricted substances. I’d advise you not to use peptides and grow muscles naturally, using protein and creatine.

    Peptides are too unexplored for anyone to use casually and are only allowed for research and medicinal applications.

    What do peptides do to your body?

    It’s important to keep in mind that peptides are naturally synthesized chains of amino acids our body produces for itself. They have natural coding, which allows them to manipulate other cells into doing what it wants them to do, be it growth, loss, or other things.

    Peptides help muscle mass gain, fat loss, recovery time, endurance, overall performance, etc. They are also often used in medicine, especially dermatology, for treating skin conditions.

    Peptides can manipulate our bodies into growing muscle faster, losing fat faster, and lessening the effects of aging (something many athletes have an issue with).

    What is muscle protein synthesis?

    Muscle protein synthesis (MPS) is the metabolic process that describes the incorporation of amino acids into bound skeletal muscle proteins. This process is important because it allows muscle fibers to change their protein structure due to loading demands or diet changes.

    This increased amino acid availability can result in greater muscle anabolism and maximize muscle protein synthesis stimulation. The protein is also produced to repair muscle damage that has been caused by intense exercise.

    What is the best peptide for fat loss?

    Many people have issues with visceral or belly fat, and no matter how hard they work at the gym, do ab workouts, or how meticulously they choose their diet, they can’t get rid of it.

    Thankfully, some peptides can help with that.


    This is called an exercise-mimic. It’s been used in medicine when treating and regulating longevity, obesity, diabetes, and helping physical performance.

    Multiple studies have demonstrated MOTS-C’s ability to enhance lipid beta-oxidation, increase thermogenic brown fat, decrease the fat gain on a high-fat diet, and improve glucose uptake during glycolysis.

    This peptide’s other helpful benefits are improving insulin sensitivity, energy production, and longevity.


    This peptide is one of the rare ones with cognitive effects, as well. It’s used and recommended mostly for fat loss, but it’s had a documented effect on cognitive functions in healthy adults with an increased risk of Alzheimer’s disease.


    This fat burning peptide possesses the fat reducing activity of HGH without the negative effects. A trial was conducted in Melbourne in 2004, where 300 obese patients reported successful medical weight loss over the course of 12 weeks (while using this peptide).


    It’s perfectly fine to use supplements, but you should always be careful.

    You have just learned the different peptides that bodybuilders use and how each of them works in helping you grow your muscles. So, the choice of which one to use depends on you.

    However, you must bear in mind that the use of peptides is considered illegal because it still requires further studies.

    Peptide FAQ

    Still have questions about what peptides are? Read on for answers to some of the more commonly asked questions about the best peptides for muscle growth.

    Who is a good candidate for peptide therapy?

    Men and women, especially athletes and bodybuilders, can benefit from peptide therapy as long as they use the right peptides. The peptides’ effects on the body depend on the sequence of amino acids the peptides contain. Collagen peptides, for example, are good for skin health and can reverse the signs of aging, while creatine peptides help build strength and muscle mass.

    What is peptide therapy most commonly used for?

    Peptide therapy is often used for soft tissue repair, accelerating the healing process, promoting lean muscle gain, improving hormone production, and improving cognitive function. Peptide hormones should only be used as prescribed by a doctor.

    What is a synthetic peptide?

    A synthetic peptide has chemically synthesized small polymers of amino acids. A synthetic peptide resembles naturally occurring peptides and is used as a standard in mass spectrometry-based applications.

    How do you know which peptide is right for you?

    When choosing peptides, make sure to choose the right form for your desired results. The best peptides are those with studies that back up their overall efficacy. The right peptides for bodybuilders will boost muscle growth, promote fat loss, and improve their overall workout performance and muscle recovery time. However, again, not many studies show proven results, and the long-term safety of GHS peptides for bodybuilders is unknown.

    Last update on 2022-10-13 / Affiliate links / Images from Amazon Product Advertising API


    James Wright

    James (36) has been working out since he was 15 years old. He has a home gym where he pumps iron, does bodyweight workouts and boxing. He likes sharing his experiences with others who want to build a better physique.

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