What Are Peptides? Everything You Need to Know About This Latest Health Trend

by Krista Russ

April 2, 2024

If you’ve watched the news or browsed social media lately, you may have noticed a lot of chatter around the topic of peptides. Perhaps, you’ve heard they can improve the look and feel of your skin, or help you lose weight. But what exactly are peptides, and do they really work?  

This article explores the ins and outs of peptides, including what they are, what they’re used for, how they can potentially benefit your health, and more.  

To find a doctor near you, simply search the Bio-Identical Hormone Therapy (BHRT) Provider Directory.

What are peptides?

Peptides are short chains of amino acids ranging from 2-50 amino acids in length that are found throughout the human body (health.com). Amino acids are the building blocks of proteins. Like beads can join to form a necklace, peptides are strung together chemically. Multiple peptide subunits can then join together to form whole proteins, which are also called polypeptides (nature.com). Enzymes, which are protein molecules themselves, can digest whole, intact proteins into shorter peptide fragments.  

Peptides serve many biological functions in the human body, including both structural and functional. They aid processes ranging from wound healing to cellular communication and more. There are two types of peptides: endogenous and exogenous. 

Endogenous Peptides 

Endogenous peptides are those which are naturally made by and found in every cell and tissue in the human body (healthnews.com). Over 7,000 peptides have been discovered in the human body to date (peptidesociety.org).  

Some functions of these naturally occurring peptides include forming hormones, enzymes, neurotransmitters, growth factors, and other biologic compounds within the body (peptidesociety.org) Examples include the hormone oxytocin, a peptide-based hormone that plays an important role in human connection and bonding, as well as the milk ejection reflex during breastfeeding (Verywell Health). Angiotensins are another type of endogenous peptide that help to control blood pressure.  

Exogenous Peptides 

Peptides can also come from outside or exogenous sources, such as those found in certain supplements, cosmetics, food, or even medications. This includes those used to manage medical conditions like cancer, infections, or infertility (health.com). The diabetes drug insulin is a well-known exogenous peptide drug. Luteinizing hormone-releasing hormone (LH-RH) agonist drugs, such as leuprolide, is a peptide drug used in IVF treatment and to treat prostate and ovarian cancer, as well as for precocious (early) puberty.  

Some peptides found in foods may have health-promoting effects like anti-inflammatory, anti-hypertensive, or anxiolytic activity as well. For example, collagen peptide supplements are commonly used for promoting healthy skin, hair, nails, and joints since it’s already a natural component of these tissues.  

Collagen peptides have been shown to increase skin elasticity and hydration and promote wound healing after burns or surgery (Verywell). It may also boost collagen density in the second layer of the skin called the dermis, reducing signs of skin aging.  

What is peptide therapy/peptide injections?

Much of the buzz surrounding peptides is about the use of peptides in the context of peptide therapy/peptides therapeutics. This could include injectable, as well as oral peptides that you take for gaining certain health benefits like reducing fat mass, retaining lean body mass, or improving your skin.  

Injectable peptides tend to offer the greatest bioavailability, meaning they are absorbed better and have higher activity compared to oral peptide forms. This is because they bypass the digestive system and are delivered directly into your circulation, reaching tissues much faster.  

However, even oral peptides have benefits over their larger, whole protein counterparts. Because peptides are much smaller molecules, they are not only absorbed more easily than intact proteins but also tend to cause fewer sensitivity and allergic reactions; this is why they’re even used in hypoallergenic baby formulas (health.com). 

Finally, because peptides are natural components of the human body, peptide-based drugs are often better tolerated when compared to other types of drugs, with fewer side effects (peptides society).  

Who Does Peptide Therapy Benefit?

A variety of individuals may benefit from the use of therapeutic peptides, including those who have: 

• Excess body weight 
• Diabetes, pre-diabetes, or insulin resistance 
• PCOS 
• Fitness/health interest 
• Menopause or andropause 
• Muscle or bone loss 
• Hair loss or skin issues  
• Autoimmune disorders 
• Brain and mood disorders 
• Sexual health issues  

Common Types of Therapeutic Peptides

Over 100 types of peptide drugs have been approved for use by the FDA in the U.S to date (WebMD). Some are derived from natural sources, and others are made synthetically in medical labs. Some include FDA-approved drugs, while others are components of nutritional supplements. Peptides that are commonly used for therapeutic purposes are discussed below.  

GLP-1 Agonist Medications 

GLP-1 agonists medications like semaglutide, which contains GLP-1/glucagon-like-peptide-1, (brand names Ozempic, Wegovy, and Rybelsus), as well as dual agonist medications like tirzepatide (brand names Mounjaro and Zepbound), which contain both GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) are remarkable, breakthrough medications for both weight loss and diabetes control. These medications work by mimicking peptide hormones naturally made by the body called incretins. GLP-1 and GIP are two types of incretin hormones.  

Incretins work by slowing stomach emptying, helping you to feel full faster. They also act directly on satiety centers located within the brain, where both GLP-1 and GIP receptors are found, powerfully suppressing hunger, including hedonic hunger or food cravings (drugs.com).  

The agonist medications are also known as “incretin mimetics” because they mimic the effects of natural incretins, except they are chemically modified to have stronger effects and last for several days rather than only a few minutes. 

PT-141/Bremelanotide  

If you have ever heard the sentiment “your biggest sex organ is your brain,” there is some truth to this statement. While the sex organs certainly play a pivotal role in sexual function, sexual desire, which typically precedes sexual activity, starts in the brain. 

PT-141, also known as bremelanotide, is one of the first drugs to uniquely target desire issues, rather than sexual function, such as PDE5 inhibitors (Viagra, Cialis, etc.).  

This peptide functions as a “melanocortin receptor (MCR) agonist”, which works by activating several melanocortin receptors within the brain (2022 paper). The activation of these receptors has been found to play an important role in human sexual desire and arousal.  

PT-141 has been approved to treat Hypoactive Sexual Desire Disorder (HSDD) in pre-menopausal women, which is characterized by the distressing absence of sexual desires or thoughts and is administered either intranasally (in your nose) or via subcutaneous injection (injection through fatty tissue directly under your skin). It has also been used successfully off-label to treat sexual issues in men and older women. It can even be paired with other meds that influence sexual arousal and performance (Viagra, Strenda, etc.) for even greater effect.  

Growth Hormone & Growth Hormone Analogs 

The injectable medication rhGH (synthetic growth hormone) and certain drugs or compounds that promote the natural release of growth hormone from the pituitary gland (called growth hormone analogs), such as sermorelin, help to increase growth hormone levels in the body (Mayo Clinic).  

Because Growth Hormone (GH) production naturally declines with age, sermorelin and GH’s ability to increase growth hormone levels may counteract some of the effects of aging, such as muscle and bone loss.  

Some of the well-documented benefits of Human Growth Hormone on the body include (per research, prior knowledge): 

• Improved body composition (↓ body fat and ↑ muscle mass) 
• Improved mood and well-being 
• Better insulin sensitivity  
• Increased skin thickness 
• Increased bone density 

• Greater physical fitness/exercise recovery  
• Better memory 
• Better sleep 
• Stronger immune system 
• Stronger libido  
• Improved erectile function 
• Improved male fertility  

Glutathione Injections 

Glutathione is a powerful antioxidant found in every tissue and cell made of three amino acids: glutamine, glycine, and cysteine (Medical News). It serves many important functions and has been found to be deficient in many chronic diseases, including the natural aging process. Some of its functions include: 

• Boosting the immune system 
• Spermatogenesis (formation of sperm) 
• Building and repairing DNA 
• Neutralizing free radicals 
• Helping enzymes work 
• Recycling other antioxidants, like Vitamins C & E 
• Helping the liver and gallbladder breakdown fat 
• Aiding apoptosis (programmed cell death), which is essential to normal growth  

Moreover, glutathione supplementation has been found in research to potentially benefit several chronic conditions, including but not limited to: Parkinson’s Disease, uncontrolled diabetes, Autism Spectrum Disorder (AUD), liver disease/fatty liver, psoriasis, peripheral artery disease, autoimmune diseases, asthma, cystic fibrosis, and potentially even cancer (Medical News, Healthline).  

You can increase glutathione levels through oral supplementation or take supplements that increase glutathione production in the body, such as the amino acid n-acetylcysteine, the enzyme superoxide dismutase, or an herb called milk thistle that helps the liver to create more glutathione.  

You can also boost glutathione levels through intravenous (IV) supplementation, which delivers glutathione through a vein. This is helpful because glutathione is often poorly absorbed as an oral supplement unless found in a liposomal form (2019 paper).  

Peptides Safety Considerations

Certain peptides have recently been banned by the FDA due to lack of research to support their safety or adverse clinical effects. These include peptides you may have heard about on the internet such as GHK-CU, a peptide used to reduce signs of skin aging and promote wound healing (2018 paper), and many of the Growth-Hormone Releasing Peptides, such as ipamorelin, CJC-1295, ibutamoren, and others that increase growth hormone secretion in the body.  

These peptides are strictly considered experimental, and their use by patients for therapeutic purposes could result in dangerous or even lethal consequences. That is why we strongly discourage you from buying these off the online black market.  

In the “Where To find Peptides” section, we discuss how to safely obtain peptides that are legal and safe from reputable, trustworthy sources. 

Peptides Side Effects

The side effects of peptides are highly dependent on the specific type of peptide drug or supplement used, but as with any medication or supplement, side effects are possible. Some are mild; others are more severe. 

Be sure to visit the drug manufacturer’s website (links below) before taking any peptide medication so that you are aware of all possible side effects and can discuss the pros and cons with your healthcare provider.  

Sermorelin Side Effects 

Growth Hormone Side Effects  

PT-141 Side Effects 

Semaglutide Side Effects 

Tirzepatide Side Effects  

Glutathione Side Effects  

Peptides Cost

Peptide therapy prices can vary widely, depending on the specific peptide used, its dosage, and length of treatment. The approximate monthly costs (without insurance) of some popular peptide therapies are as follows:  

***NOTE: when prescription drug coverage is allowed, it may substantially reduce the cost of these drugs to as low as $0/month.  

Where To Find Peptides

If you’re interested in trying peptides, it’s important that you obtain them from a safe and reliable source. While some peptides can be purchased over-the- counter as dietary supplements, such as collagen peptides, certain glutathione formulations or its precursors (n-acetylcysteine), and sarcotropin (a medical food that contains growth hormone analogs), other peptides are considered drugs and must be prescribed by a healthcare provider.  

These should be prescribed to you through a licensed healthcare provider and/or reputable medical doctor—not purchased off the black market, which is unsafe.  

Fortunately, many of our Worldlink Medical healthcare providers have a wealth of insight surrounding peptides and can help you find the right combination of peptides tailored just for you. Whether your goals are to lose weight, have more energy, or improve your cardiometabolic health, peptides can play a key role in helping you reach your health goals, which is why we recommend you schedule an appointment with a WLM-trained healthcare provider today.  

Sources:

Kubala J. Fisher S. What Are Peptides and What Are They Used For? Health. Published on March 1, 2023. Accessed on February 9, 2024. https://www.health.com/what-are-peptides-7106093 

Peptide. Scitable by nature education. Accessed March 1, 2024.  https://www.nature.com/scitable/definition/peptide-317/#:~:text=Peptides%20are%20generally%20considered%20to,proteins  

Beltran JV. Peptide Injections: Do They Work? Published on April 12, 2023. Accessed on February 9, 2024. https://healthnews.com/longevity/longevity-supplements/peptide-injections-do-they-work/ 

What Are Peptide Therapeutics? And How It Can Impact Your Clinical Care Approach. International Peptide Society. Accessed on February 9, 2024. https://peptidesociety.org/what-are-peptide-therapeutics/ 

Ajiboye T. Goel A. Everything You Need to Know About Peptides: Peptides are short chains of amino acids that can form proteins. Verywell Health. Updated on February 14, 2024. Accessed March 1, 2024. https://www.verywellhealth.com/what-is-a-peptide-5084580  

Sreenivas S. King L. Sheikh Z. Peptides: Types, Uses, and Benefits. WebMD. Medically Reviewed on February 15, 2024.  Accessed March 1, 2024. https://www.webmd.com/a-to-z-guides/what-are-peptides 

Incretin mimetics. Drugs.com: Know More. Be Sure. Accessed on February 10, 2024. https://www.drugs.com/drug-class/incretin-mimetics.html 

Edinoff AN, Sanders NM, Lewis KB, Apgar TL, Cornett EM, Kaye AM, Kaye AD. Bremelanotide for Treatment of Female Hypoactive Sexual Desire. J Neurol Int. 2022 Jan 4;14(1):75-88. doi: 10.3390/neurolint14010006. PMID: 35076581; PMCID: PMC8788464. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8788464/#:~:text=Bremelanotide%20is%20a%20melanocortin%20receptor,45%20min%20before%20sexual%20activity 

Sermorelin (Injectable Route). Mayo Clinic. Updated February 1, 2024. Accessed March 1, 2024. https://www.mayoclinic.org/drugs-supplements/sermorelin-injection-route/side-effects/drg-20065923?p=1 

O. Khorram, G. A. Laughlin, S. S. C. Yen, Endocrine and Metabolic Effects of Long-Term Administration of[ Nle27]Growth Hormone-Releasing Hormone-(1–29)-NH2 in Age-Advanced Men and Women, The Journal of Clinical Endocrinology & Metabolism, Volume 82, Issue 5, 1 May 1997, Pages 1472–1479, https://doi.org/10.1210/jcem.82.5.3943 https://academic.oup.com/jcem/article/82/5/1472/2823341 

Galan N. Carter A. What Are the Benefits of Glutathione? Medical News Today. Updated on October 4, 2023. Accessed March 1, 2024. https://www.medicalnewstoday.com/articles/323936#benefits 

Whelan C. Wilson DR. Glutathione Benefits. Healthline. Updated on April 18, 2023. Accessed March 1, 2024. https://www.healthline.com/health/glutathione-benefits#side-effects-and-risks 

Sinha R, Sinha I, Calcagnotto A, Trushin N, Haley JS, Schell TD, Richie JP Jr. Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function. Eur J Clin Nutr. 2018 Jan;72(1):105-111. doi: 10.1038/ejcn.2017.132. Epub 2017 Aug 30. PMID: 28853742; PMCID: PMC6389332. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6389332/ 

Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. Int J Mol Sci. 2018 Jul 7;19(7):1987. doi: 10.3390/ijms19071987. PMID: 29986520; PMCID: PMC6073405. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073405/