Oral, Sublingual and Intranasal Delivery Forms of Research Peptides: A Research Review of Enzymatic and Epithelial Barriers, Nose-to-Brain Transport, the Route-Specific Literature for BPC-157, SLU-PP-332, MOTS-c, Semax and Selank, and the Catalogue Vocabulary Behind "bpc-157 peptide capsules", "nasal peptide spray" and "sublingual bpc 157" Labels

Peptide Insider Research Desk · 2026-09-24 · Research Basics · Research reference only

Search logs for research peptides contain a large and growing vocabulary that has nothing to do with the lyophilised vial: bpc-157 peptide capsules, nasal peptide spray, sublingual bpc 157, slu-pp-332 oral, mots-c peptide oral. Each phrase names a delivery form — oral solid, sublingual or buccal mucosal, or intranasal — and each delivery form corresponds to a specific set of physiological barriers that the peer-reviewed literature has characterised in detail. This review lays out those barriers, summarises the route-specific studies that actually exist for the compounds most often paired with these labels, and then maps the catalogue and query vocabulary onto that record with an explicit research-use-only (RUO) scope status. It contains no dosing, preparation or administration guidance; the material is strictly for research reference and not for human or veterinary use.

1. Why Peptides Rarely Cross the Gut: The Enzymatic and Epithelial Barrier

Unformulated peptides show oral bioavailability that is usually below 1–2%, because they are hydrolysed by luminal and brush-border proteases and are too large and too polar to permeate the intestinal epithelium efficiently [1,2,3]. Drucker’s 2020 review in Nature Reviews Drug Discovery frames the problem as a sequence of hurdles: acid and pepsin in the stomach, trypsin, chymotrypsin and carboxypeptidases in the small intestine, membrane-bound aminopeptidases on the enterocyte brush border, a mucus layer that slows diffusion, and finally an epithelium whose tight junctions exclude hydrophilic molecules above roughly 500–700 Da from the paracellular path [1]. Renukuntla and colleagues catalogue the same barriers from the formulation side and group counter-strategies into enzyme inhibitors, permeation enhancers, chemical modification (lipidation, cyclisation, D-amino-acid substitution) and carrier systems [2].

The physicochemical reason peptides fail is captured by Lipinski’s rule-of-five analysis: molecules with more than five hydrogen-bond donors, more than ten acceptors, molecular mass above 500 Da or high polar surface area are statistically poor passive permeants [4]. A pentadecapeptide such as BPC-157 (1,419 Da, 15 residues) or a 16-residue mitochondrial peptide such as MOTS-c violates every criterion. The exceptions that have reached advanced development do so by engineering around the rules: the oral semaglutide tablet co-formulates the lipidated GLP-1 analogue with the absorption enhancer SNAC, which Buckley and colleagues showed acts locally in the stomach to raise pH and promote transcellular uptake across the gastric epithelium [5]. Aguirre and colleagues review the broader pipeline — enteric coatings, permeation enhancers, protease inhibitors, mucoadhesive systems — and note that even the most successful reach single-digit percentage bioavailability [3]. Liposomal carriers, which appear in the catalogue phrase liposomal bpc 157 tb 500 oral peptide, are reviewed generically by He and colleagues, who describe both their potential to shield cargo from enzymes and their instability in bile-salt-rich intestinal fluid [6].

2. Sublingual and Buccal Mucosa: A Thinner Epithelium with a Smaller Surface

The sublingual route avoids gastric acid, pancreatic proteases and hepatic first-pass metabolism, but offers a small absorptive area, short residence time and its own enzymatic activity, so it favours small lipophilic molecules rather than peptides [7]. Hearnden and colleagues describe the floor-of-mouth and buccal epithelia as non-keratinised, stratified squamous tissue 100–200 µm thick in the sublingual region and 500–800 µm in the buccal region, with a permeability barrier located in the outer third of the epithelium formed by membrane-coating granules [7]. Dosage forms designed for this interface include fast-dissolving films (the oral strips class), lozenges and troches (the ghk cu troche label), and sublingual tablets (bpc 157 sublingual tablets). None of the peptides that carry these labels in research catalogues has a peer-reviewed sublingual or buccal pharmacokinetic study that this review could locate; the terms are recorded as nomenclature. Even oxytocin, the most extensively studied mucosally delivered neuropeptide, is represented in the review literature by intranasal work [19], so sublingual oxytocin is likewise recorded rather than evidenced.

3. Intranasal Delivery and Nose-to-Brain Transport

Intranasal delivery exposes a compound to two epithelia — the vascular respiratory mucosa, which can deliver molecules to the systemic circulation, and the olfactory epithelium, from which molecules can reach the brain and spinal cord along olfactory and trigeminal nerve pathways without crossing the blood–brain barrier [8,9,10]. Illum’s review sets out the practical constraints: a nasal cavity volume of roughly 15–20 mL, mucociliary clearance with a half-time of 15–20 minutes, and a mucosal enzyme complement that includes aminopeptidases, so that peptides above about 1 kDa show low systemic nasal bioavailability unless absorption enhancers are used [8]. Lochhead and Thorne review the nose-to-brain pathway for biologics, describing extracellular transport along olfactory and trigeminal perineural spaces on a timescale of minutes rather than the hours expected for axonal transport [9]. Thorne and colleagues demonstrated the pathway directly in rats, tracing [¹²⁵I]-labelled IGF-1 from the nasal cavity to the olfactory bulb, brainstem and spinal cord [10].

Two research peptides have a genuinely intranasal literature. Semax (Met-Glu-His-Phe-Pro-Gly-Pro), an ACTH(4-10) analogue, increased BDNF and trkB expression in the rat hippocampus in the study by Dolotov and colleagues [17], and Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro), a tuftsin analogue, regulated hippocampal BDNF expression after intranasal administration in the report by Inozemtseva and colleagues [18]. These rodent findings are the origin of the nasal peptide, nasal spray peptide and peptide nose spray search vocabulary and of catalogue labels such as n-acetyl selank amidate spray, an N-terminally acetylated, C-terminally amidated analogue for which no analogue-specific data were located. Intranasal oxytocin has the largest human literature of any nasally delivered peptide; Quintana and colleagues review its methodological lessons, including the difficulty of distinguishing nose-to-brain transport from peripheral effects [19]. For the GHRH-axis blends behind cjc 1295 ipamorelin nasal spray, the peer-reviewed pharmacokinetics are subcutaneous [20]; no intranasal study of CJC-1295, ipamorelin, sermorelin or tesamorelin was located.

4. Route–Barrier–Literature Matrix

Table 1 aligns each delivery route with its principal barrier, the bioavailability descriptor used in the literature, and the compounds for which route-specific peer-reviewed models exist. The right-hand column lists compounds whose catalogue labels name the route but for which no route-specific study was located; those entries are vocabulary, not evidence.

Route / delivery form	Principal physiological barrier	Literature descriptor	Compounds with route-specific peer-reviewed models	Catalogue labels without a located route-specific study
Oral solid (capsule, tablet)	Gastric acid and pepsin; pancreatic proteases; brush-border peptidases; mucus; tight junctions [1,2]	Absolute oral bioavailability typically <1–2% for unformulated peptides [1,3]	BPC-157 (per-oral and drinking-water rodent models [11,12]); MOTS-c analogue (oral, colitis mouse model [16]); semaglutide-SNAC (gastric transcellular uptake [5])	TB-500, KPV, GHK-Cu, KLOW/GLOW blends, CJC-1295, ipamorelin, sermorelin, tesamorelin, Melanotan II, epitalon
Oral liposomal	As above, plus bile-salt destabilisation of the vesicle [6]	Enzyme shielding with variable intestinal stability [6]	Class-level review only [6]	BPC-157 + TB-500 liposomal blends
Sublingual / buccal (tablet, troche, film)	Non-keratinised stratified epithelium; membrane-coating-granule lipid barrier; salivary clearance [7]	Favours small lipophilic molecules; peptide permeability low without enhancers [7]	None located among catalogue research peptides	BPC-157, SLU-PP-332, oxytocin, sermorelin, GHK-Cu, CJC-1295/ipamorelin
Intranasal (spray)	Mucociliary clearance (t½ 15–20 min); nasal aminopeptidases; olfactory and respiratory epithelia [8]	Systemic bioavailability falls with molecular mass; nose-to-brain transport along olfactory/trigeminal routes [8,9,10]	Semax [17]; Selank [18]; oxytocin [19]; IGF-1 tracer study [10]	CJC-1295/ipamorelin, PT-141 catalogue sprays, generic “peptide nasal spray kit”
Parenteral (reference route)	None of the above; complete systemic exposure by definition	Absolute bioavailability 100% (intravenous) or high (subcutaneous) [20]	SLU-PP-332 [13]; MOTS-c [15]; CJC-1295 [20]; most compound reviews on this site	—

5. Compound-by-Compound Route Record

BPC-157. The Zagreb group has repeatedly described BPC-157 as a “stable gastric pentadecapeptide” that is stable in human gastric juice, and much of their rodent work administered the peptide per-orally, including in drinking water, alongside intraperitoneal and intragastric arms [11,12]. That is the only reason the bpc-157 pill, bpc 157 capsule and oral peptides bpc 157 vocabulary has any literature anchor at all. The studies are pharmacological models in rats; none characterises a capsule or tablet product, an arginate salt (bpc-157 arginate salt capsules), or human pharmacokinetics. The blend labels bpc 157 tb 500 oral and bpc157 tb500 capsules extend the oral claim to TB-500, a 43-residue protein fragment with no located oral model. The site’s BPC-157 stability and handling review covers the peptide’s solution stability separately.

SLU-PP-332. The query pair slu-pp-332 oral or injectable and slu pp 332 oral bioavailability has a precise answer in the primary literature. Billon and colleagues administered SLU-PP-332 parenterally in their 2024 metabolic-syndrome study in mice [13]; in 2026 the same group reported SLU-PP-915 explicitly as “an orally active” estrogen-receptor-related receptor agonist [14], a design goal that implies the parent compound’s oral exposure was a limitation. SLU-PP-332 is a small molecule, so slu-pp-332 peptide oral and sloop peptide pill misclassify it; see the SLU-PP-332 family nomenclature review.

MOTS-c. Lee and colleagues characterised the 16-residue mitochondrial-derived peptide with parenteral administration in mice [15]. Jiang and colleagues later reported an orally administered MOTS-c analogue in a dextran-sulfate-sodium colitis model [16], which is the nearest the literature comes to the mots-c peptide oral and mots-c peptide capsules labels; the native peptide in capsule form has no located study. Background is in the MOTS-c compound review.

Semax and Selank. Both heptapeptides have an intranasal rodent literature [17,18], reviewed in the Semax and Selank comparative review. The preparation queries in this cluster are declined below because they request a protocol.

GHRH-axis peptides. CJC-1295, ipamorelin, sermorelin and tesamorelin are studied by injection [20]; the labels oral cjc 1295, cjc 1295 ipamorelin oral, sermorelin peptide sublingual, oral tesamorelin peptide and tesamorelin pill form have no located route-specific study. See the CJC-1295 family review and the tesamorelin review.

Copper peptides, melanocortins and non-peptides. GHK-Cu’s literature is topical and parenteral [21] (see the GHK-Cu topical formulation review), so ghkcu pill, ghk cu pill form and oral copper peptides are recorded without evidence, as are the blend labels glow peptide oral, glow peptide pills, klow peptide capsules and kpv bpc-157 capsules (KLOW component review). mt2 peptide pill refers to the cyclic heptapeptide Melanotan II (MT-2 review); oral epitalon to the AEDG tetrapeptide (epitalon review). Two labels name compounds that are not peptides and were developed as oral small molecules: tesofensine pills (tesofensine review) and 5-amino-1mq oral (5-Amino-1MQ family review). pt141 peptide nasal spray refers to bremelanotide, whose early clinical development included intranasal formulations (PT-141 review).

6. Vocabulary Crosswalk with RUO Scope Status

Table 2 records the query and catalogue strings in this cluster verbatim, classifies the delivery form each names, identifies the canonical compound and states the literature status. Strings that request a dosage, a preparation protocol, a purchase or a vendor product are declined and listed separately; no vendor is assessed or endorsed. Related vocabulary for vial formats is in the catalogue-formats review and for solvents in the reconstitution-solvent review.

Query / catalogue strings (verbatim)	Delivery-form class	Canonical compound	Literature status	RUO scope status
bpc-157 peptide capsules; bpc-157 capsule; bpc capsules; bpc 157 capsule; bpc157 capsule; bp157 capsules; bcp157 capsules; bcp 157 oral; oral bpc 157 capsules; bpc 157 peptides capsules; oral peptides bpc 157	Oral; Oral solid	BPC-157	Per-oral rodent models exist [11,12]; no capsule-format study located	Recorded as nomenclature
bpc-157 arginate salt capsules; bpc 157 arginate salt capsules	Oral solid	BPC-157 arginate	Salt form appears in catalogues; no peer-reviewed arginate-specific PK located	Recorded as nomenclature
bpc-157 pill; bpc157 pill; bpc pills; bpc pill; bpc-157 peptide pill; bpc-157 peptide pills; bpc 157 in pill form; bpc-157 pill form; bpc-157 tablet; bpc 157 sublingual; sublingual bpc 157; bpc-157 sublingual; bpc 157 sublingual tablets	Oral solid; Sublingual; Sublingual solid	BPC-157	Per-oral rodent models [11,12]; no tablet-format study located; no peer-reviewed sublingual model located [7]	Recorded as nomenclature
bpc 157 tb 500 oral; bpc 157 and tb 500 oral; bpc-157 tb-500 oral; bpc157 tb500 capsules; bpc 157 and tb 500 capsules; bpc 157 tb 500 peptide capsules; liposomal bpc 157 tb 500 oral peptide	Oral; Oral liposomal; Oral solid	BPC-157 + TB-500	BPC-157 per-oral models only; no oral TB-500 model located; liposomal oral peptide carriers reviewed generically [6]; no compound-specific study located	Recorded as nomenclature
kpv bpc-157 capsules	Oral solid	KPV + BPC-157	No oral blend study located	Recorded as nomenclature
klow peptide capsules	Oral solid	KLOW	No oral blend study located	Recorded as nomenclature
slu-pp-332 oral; slu pp 332 oral; oral slu-pp-332; oral slu pp 332; slu-pp-332 peptide oral; slu-pp-332 oral or injectable; slu pp 332 oral bioavailability; slu-pp-332 oral bioavailability; slu pp 332 capsules; slu pp 332 peptide capsules; slu-pp-332 pills; slu pp 332 pills; slu-pp-332 pill; sloop 332 pill; sloop pill; sloop peptide pill; slu-pp-332 sublingual; slu pp 332 sublingual; sublingual slu pp 332	Oral; Oral solid; Pharmacokinetic descriptor; Route comparison query; Sublingual	SLU-PP-332	Parenteral rodent models [13]; orally active successor SLU-PP-915 reported [14]; not a peptide; route contrast discussed in Section 5; no capsule-format study located; no sublingual study located	Recorded as nomenclature
mots-c peptide oral; mots-c peptide oral supplement; mots-c peptide capsules; mots c peptide capsules; mots-c capsules	Oral; Oral solid	MOTS-c	Parenteral rodent models [15]; orally administered analogue in a colitis model [16]; supplement framing outside RUO scope; no capsule-format study located	Recorded as nomenclature
nasal peptide; nasal peptide spray; peptide spray; peptide nasal sprays; nasal spray peptide; peptide nose spray	Intranasal; Spray device	Class descriptor	Nose-to-brain literature [8,9,10]	Recorded as nomenclature
peptide nasal spray kit	Intranasal device kit	Consumable descriptor	Device vocabulary only; no protocol given	Recorded as nomenclature
n-acetyl selank amidate spray	Intranasal	Selank analogue	Parent Selank intranasal rodent model [18]; analogue-specific data not located	Recorded as nomenclature
cjc 1295 ipamorelin nasal spray; cjc 1295 ipamorelin oral; cjc 1295 ipamorelin pill form; cjc 1295 ipamorelin sublingual	Intranasal; Oral; Oral solid; Sublingual	CJC-1295 + ipamorelin	Clinical PK is subcutaneous [20]; no intranasal, oral or sublingual study located	Recorded as nomenclature
cjc-1295 pill form; oral cjc 1295; cjc-1295 oral supplement	Oral; Oral solid	CJC-1295	No oral study located [20]; supplement framing outside RUO scope	Recorded as nomenclature
pt141 peptide nasal spray	Intranasal	PT-141	Intranasal formulations appear in the clinical-development history; see compound review	Recorded as nomenclature
oral tesamorelin peptide; tesamorelin pill form	Oral; Oral solid	Tesamorelin	No oral study located	Recorded as nomenclature
sermorelin peptide sublingual; oral sermorelin peptide; sermorelin pill form; sermorelin peptide pill; sermorelin peptide pill form	Oral; Oral solid; Sublingual	Sermorelin	No sublingual study located; no oral study located	Recorded as nomenclature
ghkcu pill; ghk cu pill form; ghk cu troche	Buccal lozenge; Oral solid	GHK-Cu	Literature is topical/parenteral [21]; no oral PK located; no buccal study located [7]	Recorded as nomenclature
oral copper peptides	Oral	GHK-Cu family	No oral PK located [21]	Recorded as nomenclature
glow peptide oral; glow peptide pills	Oral; Oral solid	GLOW blend	No oral blend study located	Recorded as nomenclature
mt2 peptide pill	Oral solid	Melanotan II	Cyclic heptapeptide; no oral PK located	Recorded as nomenclature
tesofensine pills	Oral solid	Tesofensine	Small molecule developed as an oral agent; not a peptide	Recorded as nomenclature
5-amino-1mq oral	Oral	5-Amino-1MQ	Small-molecule NNMT inhibitor; not a peptide	Recorded as nomenclature
oral epitalon	Oral	Epitalon	No oral PK located	Recorded as nomenclature
sublingual oxytocin	Sublingual	Oxytocin	Reviewed literature is intranasal [19]; no sublingual model reviewed	Recorded as nomenclature
oral strips	Oral thin film	Dosage-form descriptor	Mucosal film class reviewed generically [7]	Recorded as nomenclature
peptide pill form	Oral solid	Class descriptor	Barrier physiology in Section 1 [1,2]	Recorded as nomenclature

Declined strings. The following strings were located in the same query cluster but fall outside RUO scope and are listed only so that the boundary is explicit: “slu-pp-332 oral dosage per day” (Declined - dosage); “slu-pp-332 tablet dosage” (Declined - dosage); “bpc 157 500mcg capsules” (Declined - dosage strength); “bpc-157 500mcg capsules” (Declined - dosage strength); “bpc 157 500 mcg capsule” (Declined - dosage strength); “how to make semax nasal spray” (Declined - preparation protocol); “how to make selank nasal spray” (Declined - preparation protocol); “best oral bpc 157 supplement” (Declined - promotional/supplement claim); “buy bpc 157 capsules” (Declined - commercial); “buy bpc-157 capsules” (Declined - commercial); “bpc 157 capsules for sale” (Declined - commercial); “slu pp 332 capsules for sale” (Declined - commercial); “where to buy bpc 157 capsules” (Declined - commercial); “pure bio labs glow blend 60 capsules” (Declined - vendor product token); “pure bio labs 5-amino-1mq capsules” (Declined - vendor product token); “peptide sciences bpc-157 capsules” (Declined - vendor product token); “peptide sciences bpc 157 capsules” (Declined - vendor product token); “peptide sciences bpc 157 oral” (Declined - vendor product token); “liposomal bpc-157+tb-500 oral peptide by quicksilver scientific” (Declined - vendor product token); “semax nasal spray reddit” (Declined - forum-sourced, unreviewed); “selank nasal spray reddit” (Declined - forum-sourced, unreviewed); “does bpc 157 work in pill form” (Declined - efficacy question; answered as a scope statement in the FAQ). Vendor product tokens are declined because this review assesses no supplier; dosage-strength strings are declined because fill mass in a capsule is a dosing statement.

Where to Source for Research

Lyophilised research-grade BPC-157, MOTS-c, Semax, Selank, SLU-PP-332 and the GHRH-axis peptides discussed above are catalogued as reference materials for in-vitro and analytical work by several suppliers, including Short Chain Aminos, BioPep, Catalyst Research and Apex Research Services. Availability is noted for research reference only; this review does not compare suppliers, does not assess any capsule, spray or sublingual product, and does not endorse any delivery form. Certificate-of-analysis review is discussed in the vendor-independent quality verification review.

Frequently Asked Questions

Does bpc 157 work in pill form?

This review does not evaluate efficacy. The peer-reviewed record contains rodent studies in which BPC-157 was given per-orally (including in drinking water) and the authors describe the peptide as stable in gastric juice [11,12]; no capsule- or tablet-format pharmacokinetic study was located. The question is recorded as vocabulary only, strictly for research reference.

Why do most peptides have low oral bioavailability?

Two barriers dominate: enzymatic hydrolysis by gastric pepsin, pancreatic proteases and brush-border peptidases, and poor permeation across the intestinal epithelium because peptides exceed the size and polar-surface-area limits associated with passive absorption [1,2,4]. Reported oral bioavailability of unformulated peptides is typically below 1-2% [1,3].

What is a nasal peptide spray in the research literature?

In the literature, intranasal peptide delivery refers to deposition on the nasal respiratory or olfactory epithelium, from which molecules may enter the systemic circulation or reach the central nervous system along olfactory and trigeminal pathways [8,9]. Rodent studies of Semax and Selank used this route [17,18]. No preparation or administration guidance is given here.

Is slu-pp-332 oral or injectable in published studies?

The 2024 metabolic-syndrome study administered SLU-PP-332 parenterally in mice [13]. The same group later described SLU-PP-915 as an orally active estrogen-receptor-related receptor agonist [14], which is why oral bioavailability appears in the query vocabulary. SLU-PP-332 is a small molecule, not a peptide.

Is there a sublingual bpc 157 study?

No peer-reviewed sublingual or buccal BPC-157 study was located for this review. Sublingual delivery of any molecule depends on the thin, non-keratinised floor-of-mouth epithelium described in the oral-mucosal literature [7]; catalogue terms such as "bpc 157 sublingual tablets" are recorded as nomenclature only.

Is there an oral MOTS-c model in the literature?

The original MOTS-c work used parenteral administration in mice [15]. A 2023 study reported an orally administered MOTS-c analogue in a dextran-sulfate-sodium colitis mouse model [16]. Neither study concerns capsule products, and no human or veterinary use is implied.

Works Cited

1. Drucker DJ. Advances in oral peptide therapeutics. Nat Rev Drug Discov. 2020;19(4):277-289. PMID 31848464. DOI 10.1038/s41573-019-0053-0
2. Renukuntla J, Vadlapudi AD, Patel A et al. Approaches for enhancing oral bioavailability of peptides and proteins. Int J Pharm. 2013;447(1-2):75-93. PMID 23428883. DOI 10.1016/j.ijpharm.2013.02.030
3. Aguirre TA, Teijeiro-Osorio D, Rosa M et al. Current status of selected oral peptide technologies in advanced preclinical development and in clinical trials. Adv Drug Deliv Rev. 2016;106(Pt B):223-241. PMID 26921819. DOI 10.1016/j.addr.2016.02.004
4. Lipinski CA, Lombardo F, Dominy BW et al. Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings. Adv Drug Deliv Rev. 2001;46(1-3):3-26. PMID 11259830. DOI 10.1016/s0169-409x(00)00129-0
5. Buckley ST, Bækdal TA, Vegge A et al. Transcellular stomach absorption of a derivatized glucagon-like peptide-1 receptor agonist. Sci Transl Med. 2018;10(467). PMID 30429357. DOI 10.1126/scitranslmed.aar7047
6. He H, Lu Y, Qi J et al. Adapting liposomes for oral drug delivery. Acta Pharm Sin B. 2019;9(1):36-48. PMID 30766776. DOI 10.1016/j.apsb.2018.06.005
7. Hearnden V, Sankar V, Hull K et al. New developments and opportunities in oral mucosal drug delivery for local and systemic disease. Adv Drug Deliv Rev. 2012;64(1):16-28. PMID 21371513. DOI 10.1016/j.addr.2011.02.008
8. Illum L. Nasal drug delivery - recent developments and future prospects. J Control Release. 2012;161(2):254-63. PMID 22300620. DOI 10.1016/j.jconrel.2012.01.024
9. Lochhead JJ, Thorne RG. Intranasal delivery of biologics to the central nervous system. Adv Drug Deliv Rev. 2012;64(7):614-28. PMID 22119441. DOI 10.1016/j.addr.2011.11.002
10. Thorne RG, Pronk GJ, Padmanabhan V et al. Delivery of insulin-like growth factor-I to the rat brain and spinal cord along olfactory and trigeminal pathways following intranasal administration. Neuroscience. 2004;127(2):481-96. PMID 15262337. DOI 10.1016/j.neuroscience.2004.05.029
11. Sikiric P, Seiwerth S, Rucman R et al. Stable gastric pentadecapeptide BPC 157: novel therapy in gastrointestinal tract. Curr Pharm Des. 2011;17(16):1612-32. PMID 21548867. DOI 10.2174/138161211796196954
12. Sikiric P, Seiwerth S, Rucman R et al. Brain-gut Axis and Pentadecapeptide BPC 157: Theoretical and Practical Implications. Curr Neuropharmacol. 2016;14(8):857-865. PMID 27138887. DOI 10.2174/1570159x13666160502153022
13. Billon C, Schoepke E, Avdagic A et al. A Synthetic ERR Agonist Alleviates Metabolic Syndrome. J Pharmacol Exp Ther. 2024;388(2):232-240. PMID 37739806. DOI 10.1124/jpet.123.001733
14. Billon C, Appourchaux K, Côté I et al. An orally active estrogen receptor-related receptor agonist, SLU-PP-915, enhances aerobic exercise capacity. J Pharmacol Exp Ther. 2026;393(1):103787. PMID 41421047. DOI 10.1016/j.jpet.2025.103787
15. Lee C, Zeng J, Drew BG et al. The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metab. 2015;21(3):443-54. PMID 25738459. DOI 10.1016/j.cmet.2015.02.009
16. Jiang J, Chang X, Nie Y et al. Orally administered MOTS-c analogue ameliorates dextran sulfate sodium-induced colitis by inhibiting inflammation and apoptosis. Eur J Pharmacol. 2023;939:175469. PMID 36528071. DOI 10.1016/j.ejphar.2022.175469
17. Dolotov OV, Karpenko EA, Inozemtseva LS et al. Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Res. 2006;1117(1):54-60. PMID 16996037. DOI 10.1016/j.brainres.2006.07.108
18. Inozemtseva LS, Karpenko EA, Dolotov OV et al. Intranasal administration of the peptide Selank regulates BDNF expression in the rat hippocampus in vivo. Dokl Biol Sci. 2008;421:241-3. PMID 18841804. DOI 10.1134/s0012496608040066
19. Quintana DS, Lischke A, Grace S et al. Advances in the field of intranasal oxytocin research: lessons learned and future directions for clinical research. Mol Psychiatry. 2021;26(1):80-91. PMID 32807845. DOI 10.1038/s41380-020-00864-7
20. Teichman SL, Neale A, Lawrence B et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006;91(3):799-805. PMID 16352683. DOI 10.1210/jc.2005-1536
21. 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;19(7). PMID 29986520. DOI 10.3390/ijms19071987

Research-use-only disclaimer. This article is a literature review of delivery-route physiology and catalogue nomenclature. It contains no dosing, preparation, formulation or administration guidance, evaluates no commercial capsule, spray or sublingual product, and makes no claims about human or animal health. All compounds discussed are strictly for research reference; not for human or veterinary use.