Sublingual tablets, troches and drops are sold as the needle-free version of peptides from BPC-157 to sermorelin. "Sublingual peptides" is searched about 590 times a month. The question underneath is simple and measurable: how much of a peptide held under the tongue reaches the blood?
For two peptides, someone measured it. This page sets out those measurements, why the mouth is a hard route for peptides, and what has not been measured. Sermorelin troches have their own page, our sermorelin tablets and nasal spray page, and swallowed peptides are on our oral peptides page; neither is restated. GLP-1 drops and tablets belong to GLP1 Ledger. Nothing here is a recommendation.
The one approved sublingual peptide
On 7 October 2026 Drugs@FDA returned one sublingual peptide product: NOCDURNA, desmopressin acetate sublingual tablets (NDA 022517, Ferring), approved in June 2018 for night-time urination caused by excess urine production. Both strengths, 27.7 and 55.3 micrograms, are now listed as discontinued.
Its label is the best measurement of a sublingual peptide in the public record. It reports that "the overall mean absolute bioavailability of desmopressin administered sublingually … was 0.25% (95% CI 0.21–0.31%)", measured at 200, 400 and 800 micrograms — four to sixteen times the label's maximum dose in men. The tablet is placed under the tongue "without water" and kept there until it dissolves; women's labelled dose was half the men's, because women were more sensitive to low sodium.
Two things made the route workable for desmopressin and are not true of most research peptides. It is small — nine amino acids, 1,069 daltons. And it is potent: a fraction of a microgram in the blood is enough to act on the kidney. At 0.25%, a 55.3 microgram tablet delivers roughly 0.14 micrograms, and the drug works at that level.
What was measured for other peptides
| Peptide | Size | Study | Sublingual dose | Absorbed | Note |
|---|---|---|---|---|---|
| Desmopressin | 9 aa, 1,069 Da | NOCDURNA label (2018) | 200–800 mcg | 0.25% | The approved product |
| Desmopressin | Same | Steiner et al. 2006, 16 men | 20–320 mcg | Below detection under 80 mcg; 240 mcg ≈ 20 mcg nasal | "Very high inter-individual variability" |
| Oxytocin | 9 aa, 1,007 Da | De Groot et al. 1995, 6 men | 684 mcg (400 IU) | 0.007–0.07% | Tenfold spread; "would not seem a reliable route" |
| Desmopressin, new tablet formulation | Same | Fransén et al. 2009 | — | No improvement over the existing tablet | A nasal powder in the same study tripled nasal absorption |
| Insulin, calcitonin | 51 aa; 32 aa | Formulation and animal studies, 2014–2025 | — | Not measured in people | Nanoparticles, microemulsions, 3D-printed scaffolds |
| BPC-157, sermorelin, ipamorelin, TB-500 | 15–44 aa | None found | — | Not measured | Sold as troches and drops |
Every abstract and the label were opened on 7 October 2026. A PubMed search for sublingual administration of insulin, calcitonin, oxytocin, BPC-157, semaglutide or desmopressin among clinical trials returned 38 records; apart from desmopressin, most were about sublingual misoprostol compared with injected oxytocin in childbirth — a different drug given by mouth — and none measured a research peptide.
The Steiner result is the most practical: it took 240 micrograms under the tongue to match 20 micrograms in the nose, and the nose itself is an inefficient route (our peptide nasal spray page has those figures).
Why the mouth is hard for peptides
The lining under the tongue is thin and well supplied with blood, which is why it works for nitroglycerin and other small molecules. Three things work against peptides there:
- Size. The molecules that cross the mouth lining easily are small and fat-soluble. Peptides are large and water-soluble. Desmopressin and oxytocin are among the smallest peptide drugs in use, and they were absorbed at a quarter of a percent or less. BPC-157 is about a third larger; sermorelin (3,358 daltons) and the growth-hormone analogues are larger still.
- Enzymes. Saliva and the mouth lining contain peptidases that break peptides down.
- Swallowing. A tablet or troche that takes minutes to dissolve washes into the throat with saliva, and the swallowed portion faces the stomach — the problem described on our oral peptides page.
What the figures mean for a troche
Compounding pharmacies and telehealth services list sermorelin troches at 500 to 1,000 micrograms (sources and dates on our sermorelin tablets page). Purely as arithmetic, and borrowing a figure that belongs to a smaller molecule:
| Troche | At desmopressin's 0.25% | At oxytocin's 0.07% (upper) | At oxytocin's 0.007% (lower) |
|---|---|---|---|
| 500 mcg | 1.25 mcg | 0.35 mcg | 0.035 mcg |
| 1,000 mcg | 2.5 mcg | 0.7 mcg | 0.07 mcg |
For comparison, the adult sermorelin trials injected 0.5 to 2 mg under the skin. These numbers are not a measurement of any troche; they show the scale of the gap that a real measurement would have to close. Nobody has published one.
What is not established
- The sublingual absorption of any research peptide — BPC-157, sermorelin, ipamorelin, CJC-1295, TB-500, semax, selank or any blend. Not measured.
- Whether any sublingual research peptide has an effect in people. No trial.
- Whether flavoured troches, drops or dissolving films differ from tablets for peptides. Not studied.
- Why NOCDURNA was discontinued. Drugs@FDA lists the status; the reason was not found in the record searched.
Sources and dates
- NOCDURNA (desmopressin acetate) sublingual tablets, prescribing information, Ferring, Reference ID 4280899 (2018), FDA label PDF, sections 2 and 12.3. Read 2026-10-07.
- Drugs@FDA via openFDA, NDA 022517: both NOCDURNA strengths "Discontinued"; original approval submission dated 2018-06-21. Queried 2026-10-07.
- De Groot AN et al. Bioavailability and pharmacokinetics of sublingual oxytocin in male volunteers. J Pharm Pharmacol 1995;47(7):571–5. PMID 8568623. Read 2026-10-07.
- Steiner IM et al. Plasma pharmacokinetics of desmopressin following sublingual administration: an exploratory dose-escalation study in healthy male volunteers. Int J Clin Pharmacol Ther 2006;44(4):172–9. PMID 16625986. Read 2026-10-07.
- Fransén N, Bredenberg S, Björk E. Clinical study shows improved absorption of desmopressin with novel formulation. Pharm Res 2009;26(7):1618–25. PMID 19296208. Read 2026-10-07.
- PubChem molecular weights: desmopressin CID 5311065 (1,069.2), oxytocin CID 439302 (1,007.2), BPC-157 CID 9941957 (1,419.5), sermorelin CID 16132413 (3,357.9). Read 2026-10-07.
- PubMed: sublingual[tiab] AND (insulin[ti] OR calcitonin[ti] OR oxytocin[ti] OR BPC[tiab] OR semaglutide[tiab] OR desmopressin[ti]) AND clinical trial[pt] — 38 records, queried 2026-10-07.