Since the original therapeutic peptide, insulin was discovered in 1921, peptide research has gone far away. Today there are more than 80 peptide drugs marketed globally, attesting to their importance in modern medicine.
These types of drugs have gained popularity in recent years because there are now so many naturally occurring peptides, which play significant roles in the body. Oxytocin, vasopressin, and gonadotropin-releasing hormone, for example, control everything from mood to water balance and reproduction.
Among the most significant benefits of peptide therapy is its ability to reach into tissues like the skin and intestines. Peptides, in contrast to larger biomolecules such as antibodies, can enter the bloodstream more rapidly, and act quicker.
Another important advantage is that peptides usually cause lesser immune response and are more precise in their targeting of specific proteins. While small molecule drugs can only be effective against a small proportion of the human genome, peptides offer much higher selectivity, and this can lead to more efficient and targeted treatments.
What Are Oral Peptides?
Oral peptides are a type of drug that is taken orally, in the form of a pill. We should mention that most peptides aren’t effective if taken orally because a little of it is available for the body to use. This is called bioavailability, or a measurement of how well a substance succeeds in reaching the site in the body where it’s intended to function. For peptides, bioavailability measures how much substance reaches its biological target.
Let’s take Sermorelin, for instance: Its bioavailability explains how much of it acually gets to and stimulates the growth hormone-releasing (GHRH) receptor. It is worth noting here that bioavailaibility applies to diffrenet types of administration, not just oral one. It can even be used to describe injected peptides.
How Do Oral Peptides Work?
Peptide therapy acts in a diverse way. Depending on their structure and function, peptide drugs can act as hormones, growth factors, neurotransmitters, ion channel ligands, or even as anti-infective agents. They typically act by binding to cell surface receptors specific to them, causing targeted effects on the body. Due to their high specificity and decent binding affinity, peptides can cause precise biological responses. Therapeutic peptides function in a similar way as biologic drugs, such as antibodies or proteins, with a few important differences. They provoke fewer immune reactions and are cheaper to manufacture.
In a breakthrough study published in Nature Chemical Biology, researchers from Professor Christian Heinis’s lab at EPFL have made a major advancement in drug development. Their work paves the way for a new class of orally available medications, overcoming a long-standing challenge in the pharmaceutical field.
“There are many diseases where we know the target, but we’ve struggled to develop drugs that can effectively bind the reach them,” explains Heinis. This is especially true for many cancers, where critical protein-protein interactions drive tumor growth but remain difficult to inhibit.
The team centered their research on cyclic peptides, specialized molecules known for their ability to bind tightly and selectively to complex disease targets. Despite their potential, turning cyclic peptides into oral medications has remained a challenge, mainly because they tend to break down quickly or are poorly absorbed in the digestive system.
Cyclic peptides hold huge promise for drug development because they can latch onto targets that conventional drugs miss. However, their inability to be taken orally, like in a pill form, has severely limited their use.
Best Oral Peptides
While the majority of peptides have to be injected, there are some that can be taken orally thanks to advances in biochemical engineering. Scientists have discovered ways of protecting peptides from stomach acid or making them more absorbable, and oral delivery is a genuine option in certain cases. Here are some key examples of oral peptides and how they work.
BPC 157 peptide injection vs oral
BPC-157 is a peptide derived from a natural ‘body protection compound’ and is known for its wound healing and anti-inflammatory effects, especially in the GI tract. It has been researched for Crohn’s disease, ligament injury, and burns.
Though stomach acid resistant, BPC 157 is not well absorbed into the blood and injections are therefore preferable for non-GI diseases. For GI diseases, however, the oral route is effective because the action is local. Two forms exist: BPC 157 acetate, which is mostly given by injection, and BPC 157 arginate, 90% stable in gastric acid and ideal for oral administration.
Ac-SDKP
Ac-SDKP is a four-amino-acid peptide of the thymosin beta-4 protein. Though the whole protein is too large for oral administration, Ac-SDKP retains benefits including anti-inflammation and promotion of blood vessel growth. Its resistance to acid and small molecular structure makes it suitable for oral administration, and research is currently underway for its use in hypertension and cardiac disease.
5-Amino-1 MQ
5-Amino-1 MQ is a 1-methylquinolinium-based small molecule (159 g/mol). It’s stomach acid-resistant and easuly absorbed, making it highly bioavailable. It’s researched for fat loss, insulin sensitivity, loweered cholesterol, and potential anti-cancer effects.
KPV
KPV, a three-amono-acid derivative of alpha-melanocyte-stimulating hormone, has anti-inflammatory activity even though the parent hormone is too big to be administered orally. KPV is well absorbed and can be administered orally, topically or by injection and is being investigated for GI, lung, and joint inflammation.
Larazotide
Larazotide is a synthetic peptide from a cholera toxin component but is therapeutic and safe. It controls intestinal tight junctions and does not need to enter the bloodstream to exert its effects, so oral delivery is ideal. It is being studied in clinical trials for celiac disease, diabetes, and other GI diseases.
MK-677 (Ibatumoren)
MK-677 mimics ghrelin and stimulates the secretion of growth hormone. It is, nonetheless, active orally, unlike ghrelin, and is researched for various conditions including muscle gain, better sleep, and higher bone density.
NMN (Nicotinamide Mononucleptide)
This oral peptide is a small molecule that has a role in energy metabolism and anti-aging. It can enhance insulin sensitivity and lipid metabolism and is stable and can be absorbed through the GI tract, making it highly effective through oral administration.
PEA (Palmitoylethanolamide)
PEA is not a peptide but behaves like one. This fatty acid decreases pain and inflammation and supports the nervous system. It’s naturally stable in the stomach and is being researched for diseases like Alzheimer’s.
Tesonfensine
Tesonfensine is a serotonin-noradrenaline-dopamine reuptake inhibitor that was initially developed to treat obesity in animal models. Although not a peptide, it is orally bioavailable (<90%) and can lead to significant weight loss.
Tributyrin
This is a fatty acid that is metabolized to butyric acid in the bloodstream. While butyric acid is broken down in the stomach, tributyrin is known to be stable. It has the potential to prevent the growth of colon cancer cells and is a very good example of a prodrug, a compound that is designed to become active after digestion.
Oral Peptides vs Injectable
Injectable peptides are delivered straight into the bloodstream, which allows them to work quickly and efficiently. Because of this direct route, injections are often the go-to method in both medical treatments and performance-enhancing protocols.
Using injectable peptides usually involves a few key steps:
- Carefully reconstituting the peptide powder
- Mixing it with a sterile liquid, often bacteriostatic water
- Administering the injection with a clean, sterile syringe
Reconstitution is especially important, it needs to be done with precision and in clean conditions. Doing it right helps maintain the stability and potency of the peptide while reducing the risk of contamination.
What makes injectable peptides appealing?
- Fast and noticeable effects
- High bioavailability (your body absorbs more of the active compound)
- Accurate dosing
- Great for targeted results, whether for healing, muscle growth, or hormone support
Oral Peptides: A Convenient Alternative
Unlike injections, oral peptides or peptides pills are taken orally and absorbed through the GI tract. They take a bit longer to kick in, but they come with some major advantages, especially when it comes to their use.
Why do some people prefer oral peptides?
- Super easy and non-invasive – no needles required
- More comfortable for long-term use
- Often better compliance (people are more likely to stick to their routine)
- Typically have a longer shelf life
To protect the peptides from being broken down by stomach acid, many oral forms are encapsulated. This helps them survive the journey to the intestines, where they can be absorbed. Even with encapsulation, though, their bioavailability is generally lower than injectables, but ongoing research is finding ways to improve that.
Want to dive deeper into advanced GLP‑1 therapies?
Some multi-receptor agonists are reshaping how we approach obesity and metabolic health.
Read more about Retatrutide and its potential as a next-generation treatment.
References:
- Chang, C.-H., Tsai, W.-C., Lin, M.-S., Hsu, Y.-H., Su Pang, J.-H., & Xu, B. (2022). Pharmacokinetics, distribution, metabolism, and excretion of body‑protective compound 157, a potential drug for treating various wounds, in rats and dogs. Frontiers in Pharmacology. https://pubmed.ncbi.nlm.nih.gov/36588717
- Skorijev, [et al. – replace with correct first author initials if needed]. (2019). Gastric pentadecapeptide BPC‑157 and wound healing. Journal of Applied Physiology. https://pubmed.ncbi.nlm.nih.gov/34267654
- Leffler, D. A., Kelly, C. P., Abdallah, H. Z., Colatrella, A. M., Harris, L. A., Leon, F., … Murray, J. A. (2012). A randomized, double‑blind study of larazotide acetate to prevent the activation of celiac disease during gluten challenge. American Journal of Gastroenterology, 107(10), 1554–1562. https://pubmed.ncbi.nlm.nih.gov/22825365
- Kelly, C. P., Green, P. H., Murray, J. A., DiMarino, A., Colatrella, A., Leffler, D. A., … Fedorak, R. N. (2013). Larazotide acetate in patients with celiac disease undergoing a gluten challenge: a randomized placebo‑controlled study. Alimentary Pharmacology & Therapeutics, 37(2), 252–262. https://pubmed.ncbi.nlm.nih.gov/23163616
- Di Sabatino, A., et al. (2021). Larazotide acetate for persistent symptoms of celiac disease despite a gluten‑free diet: a randomized controlled trial. Gastroenterology, 148(X), 1311–1319.e6. https://pubmed.ncbi.nlm.nih.gov/25683116
- Nagai, K., Nitta, Y., … [et al.] (2014; 2016). Oral administration of Ac‑SDKP cured kidney fibrosis in rats. https://pmc.ncbi.nlm.nih.gov/articles/PMC6824425
Our support team is at your service, ensuring customer satisfaction.
