If you’re trying to build muscle, you’re probably familiar with the basics: eat plenty of protein and add resistance training into your workout routine. But if you’re looking for an extra boost, you may have also come across a variety of supplements and aids in your research like peptides.
Peptides are a popular group of supplements that primarily work to increase muscle growth by activating the production of hormones that are necessary for hypertrophy and performance in the gym.
Peptides are rapidly absorbed and seem to have fewer side effects than other performance-enhancing aids like steroids.
Many peptides that influence the production of growth hormones are banned by legal bodies and sports organizations.
The use of peptides for muscle mass is a promising field of research, but more studies need to be done to determine what their long-term effects are and whether they are a viable means of increasing muscle gain.
Peptides are a popular class of performance-enhancing aids that are said to spur muscle growth and maximize your gym performance, and they have even earned a reputation as a safe and natural alternative to steroids. But do they work — and are they safe? Here’s what you should know about peptides for bodybuilding.
What are peptides?
Peptides are short chains of amino acids, which are molecules that act as the “building blocks” of all of your body’s tissues, organs, and systems.
Peptides are sometimes confused for proteins since both are made of long strings of bonded amino acids. However, unlike protein molecules, which are long strings of amino acids, peptides are usually made of shorter chains of less than 50 amino acids.
Your body naturally makes several kinds of peptides, and each peptide plays a specialized role. You can also find peptides in a variety of protein-rich food sources like meat, fish, and legumes. In addition, more and more focus is being placed on synthetic peptide supplements, which mimic the effects that natural peptides have on your body.
How do peptides work?
Peptides can play various roles, but one of the most important for bodybuilding and muscle gain is their ability to influence your body’s creation of hormones.
Peptides can act on your pituitary gland, an organ in your brain responsible for releasing hormones. Hormones act as your body’s “chemical messengers,” so the increased production means that they can then go on to take action on a wide variety of functions in your body.
Because peptides have so many potential applicable benefits, peptide therapy is becoming an increasingly popular option for people looking to address a variety of health concerns. Supplemental synthetic peptides come in two different forms: injectable and oral.
Some advantages of peptide therapy include:
- Boosting your immune system.
- Preventing signs of aging (wrinkles, sagging, damage) in skin.
- Boosting energy levels.
- Protect heart health.
- Improving sleep and sleep quality.
- Encourage muscle growth.
Muscle-building peptides are a particularly promising aid for people looking to increase their performance and recovery in the gym — and increase their lean muscle mass in the process.
How can peptides encourage muscle growth?
Because peptides can influence hormone production, targeted peptide therapies can potentially increase the production of hormones related to muscle growth and athletic performance.
Take growth hormone secretagogues (GHS), for example. These peptides are thought to help stimulate your body’s release of specific hormones like human growth hormone (HGH), which directly impacts muscle growth. In addition, your natural production of HGH decreases as you grow older, which is why you may see a loss of muscle mass as you age.
And what if you’re trying to lose weight? Some evidence suggests that yes, certain peptides may help improve body fat percentage as well. For example, a study that evaluated the effects of collagen peptide supplementation in 97 middle-aged, untrained men who also participated in a 12-week resistance training program saw significant increases in fat-free mass as well as a decrease in body fat when compared to participants in the study who were not administered the collagen peptide.
Best peptides for bodybuilding
Some of the best peptides for muscle growth include creatine peptides, collagen peptides, and growth hormone secretagogues (GHS). Creatine and collagen can generally be found in supplements like powders and pills and are thus good oral peptides for muscle growth, while you are more likely to find growth hormone secretagogues in injectable form.
Creatine is an amino acid that is stored in your muscles and thus has plenty of potential benefits when paired with the right workout. Creatine monohydrate supplements are popular ergogenic aids that are well known for their ability to boost energy, increase strength, and maximize muscle mass hypertrophy from your workouts. But creatine peptides are becoming bigger and more popular as a workout aid, especially since they are thought to be more rapidly absorbed and easier on the gut than other forms of creatine.
Growth hormone secretagogues (GHS)
This class of muscle-building peptides comprises several different peptides, and all of them use different mechanisms. However, the end goal is always the same: to increase the amount of growth hormone that is created by your body to augment your muscle growth.
For example, growth hormone-releasing peptides (GHRPS) are synthetic peptides that act on either the pituitary gland or the hypothalamus to encourage the release of growth hormone-releasing hormone (GHRH). As its name suggests, GHRH can then trigger the release of growth hormones to augment muscle hypertrophy.
Meanwhile, MK-677 is a ghrelin mimetic, which is a peptide that acts like the hormone ghrelin. Ghrelin is a natural hormone that also stimulates the release of growth hormones in the body. A clinical trial found that the daily administration of oral MK-677 in healthy older adults significantly increased levels of growth hormone (GH) and insulin growth factor-1 (IGF1) to levels comparable to healthy young adults.
Finally, it’s also worth noting that collagen peptides for bodybuilding can also be used for hypertrophy, though they are generally not as effective as growth hormone secretagogues. Collagen peptides are perhaps most commonly used to promote healthier, better-hydrated skin, but the evidence is also suggesting that it may play a role in promoting muscle mass as well when paired with muscle-building exercises. For example, a small study on healthy young men found that collagen peptide supplementation led to more pronounced increases in body mass, fat-free mass, and muscle strength than resistance training alone.
Side effects of peptides used for muscle growth
So peptides are promising aids for muscle hypertrophy. But because they influence hormone levels, it’s well worth considering their potential side effects as well.
Peptides have been researched for a variety of therapeutic uses, but the use of peptides for muscle growth is still relatively new. As such, there is not a ton of research out there on the long-term effects of synthetic peptides on muscle growth.
With that said, peptides do seem to be fairly well-tolerated in the short term. For example, a review that evaluated several available studies found that the use of growth hormone secretagogues was generally safe. However, they also noted that there was some concern that the use of these drugs could lead to elevated blood sugar levels since they can decrease insulin sensitivity.
In another study, researchers found that the use of ghrelin mimetic MK-677 was linked to side effects including temporary appetite increases, fluid retention, and muscle pain.
Do peptides work like steroids?
Peptides are sometimes compared to steroids, which are commonly taken by athletes looking to maximize muscle hypertrophy. However, their mechanisms — and subsequent effects on your body — are different.
Anabolic steroids are performance-enhancing drugs that primarily work to increase muscle mass by mimicking testosterone, a naturally occurring sex hormone that plays roles in stimulating muscle tissue growth. On the other hand, peptides act on your pituitary gland to stimulate your body’s natural production of hormones.
In other words: injecting synthetic steroids immediately increases the amount of circulating hormones in your bloodstream whereas injecting peptides increases the natural process of hormone production and can thus indirectly increase levels of certain hormones including testosterone and growth hormone.
The use of steroids also comes with a wide variety of adverse side effects like aggression, cardiovascular system damage, decreased sperm production and increased risks of testicular cancer. Current research suggests that the use of peptides does not seem to have these same side effects and may therefore be safer and healthier than anabolic steroid use (though more research still needs to be done to see what happens long-term).
Is it safe to take peptides for muscle growth?
Muscle-building peptides generally seem to be safe and effective. But we don’t have enough information yet to conclude whether the benefits of taking peptides for muscle growth outweigh the risks, especially since there isn’t enough research on their long-term effects. What’s more: growth hormone peptides are not legal dietary supplements and are even banned in many sports organizations.
The bottom line: while there is promising evidence that certain peptides can make a difference in your body composition, we don’t know how safe they are yet (and in many cases, they aren’t legal, to begin with). If you are interested in using peptides for muscle growth, your best bet is to talk to a doctor to see whether you are a candidate for peptide therapy.
- Science Direct. Peptide Hormone - an overview.
- Nature. Therapeutic peptides: current applications and future directions.
- The World Journal of Men’s health. Growth Hormone and Aging: Updated Review.
- International Journal of Environmental Research and Public Health. The Influence of Specific Bioactive Collagen Peptides on Body Composition and Muscle Strength in Middle-Aged, Untrained Men: A Randomized Controlled Trial.
- Current Sports Medicine Reports. Creatine Supplementation: An Update.
- European Journal of Endocrinology. Growth hormone-releasing peptides.
- HHS Public Access. Effects of an Oral Ghrelin Mimetic on Body Composition and Clinical Outcomes in Healthy Older Adults: A Randomized, Controlled Trial.
- Nutrients. Effects of 12 Weeks of Hypertrophy Resistance Exercise Training Combined with Collagen Peptide Supplementation on the Skeletal Muscle Proteome in Recreationally Active Men.
- HHS Public Access. The Safety and Efficacy of Growth Hormone Secretagogues.