Why We Do Not Compound Peptides Into Troches
A troche is made by melting a base, stirring the active into it, and pouring the mixture into a mold. That works well for a great many drugs. It works poorly for peptides, and when a prescriber asks us for a peptide troche, we say so and offer a different route instead.
How a troche is actually made
A troche is molded rather than compressed. The base is melted to a liquid, the active ingredient is dispersed evenly through it, the mixture is poured into a mold, and it sets as it cools.
Polyethylene glycol troche bases melt in a range around 42 to 51 degrees Celsius (Different troche-bases have different melting ranges), and the mixture has to stay molten long enough to be stirred to uniformity and poured. That is not a brief exposure. The active sits in warm liquid through the whole of it.
For most small molecules this is entirely fine. Testosterone, estradiol, anastrozole and many others tolerate it without difficulty, which is why we make troches for those all the time. You can read how the format works in our guide to troches as a dosage form.
Why heat is the first problem
Peptides are chains of amino acids folded into a specific shape, and that shape is what makes them work. Heat unfolds it. A denatured peptide is chemically still present in the preparation but no longer the molecule the prescriber intended to give.
Warmth also accelerates the chemical routes by which peptides break down, including hydrolysis of the bonds between amino acids, deamidation, oxidation and aggregation into clumps. These are the reasons peptide products are so often refrigerated, shipped cold, or supplied as a dry powder to be reconstituted just before use.
Holding a peptide in molten base is close to the opposite of that handling. We do not have a way to make a troche without it.
The finished troche looks perfectly normal. It has the right weight, the right colour, the right texture. Nothing about it tells the patient or the prescriber how much intact peptide survived the process, and a compounding pharmacy has no routine way to assay that in a one off preparation. A product that may or may not contain what the label says is not something we are willing to dispense.
Three more reasons the mouth is hostile to peptides
Even if a peptide survived compounding intact, the oral cavity is a difficult place to deliver one. Three separate obstacles apply, and they compound each other.
| Obstacle | What happens | Why it matters for a troche |
|---|---|---|
| Enzymes in saliva | Saliva and oral tissue contain peptidases that break peptide bonds | A troche is held in the mouth for several minutes, which is a long exposure |
| Molecular size | Peptides are large and water loving compared with the small lipophilic molecules that cross mucosa well | The lining of the mouth is a poor route for a molecule of that size |
| Swallowing | Saliva that is swallowed carries drug to the stomach | Gastric acid and digestive enzymes degrade peptides, which is why peptides are rarely given by mouth at all |
Put together, a peptide troche asks a fragile molecule to survive heat, then enzymes, then a barrier it is poorly suited to cross, with anything left over swallowed into a digestive tract built to take peptides apart.
Why we prefer the nasal route
A nasal spray is compounded as a solution at room temperature, so no heating step is involved. That alone removes the largest of the problems above.
The nasal route also suits the molecule better. The lining of the nose is thin and richly supplied with blood vessels, absorption from it enters the circulation directly rather than passing through the gut and liver first, and the residence time is short so enzymatic exposure is limited compared with several minutes in the mouth.
This is not a theory we invented. Peptides delivered nasally are established in approved medicine, with FDA approved peptide nasal sprays including desmopressin and calcitonin salmon. Nasal preparations are also non sterile, which places them inside our scope where injectables are not.
The honest limits of nasal delivery
Nasal is better than a troche for a peptide. It is not equivalent to an injection. Any prescriber choosing this route should know what the trade offs are.
What the nasal route offers
- No heating step during compounding
- Direct entry to the circulation, bypassing the gut and first pass metabolism
- Short residence time, so less enzymatic exposure
- A metered device, so each actuation delivers the same volume
- Non sterile, so it sits within our scope
What it does not offer
- Bioavailability comparable to injection, which is generally much lower nasally
- Predictable absorption when the patient has a cold or nasal congestion
- Good delivery for very large peptides, where size still limits crossing
- Freedom from local effects such as nasal irritation or dryness
- FDA approval, since a compounded nasal preparation is not an approved product
Sermorelin as a worked example
Sermorelin acetate is a 29 amino acid analogue of growth hormone releasing hormone, and it is the peptide we are asked about most often. Everything above applies to it directly, since it is a peptide of substantial size.
Its regulatory history is worth stating precisely. Sermorelin acetate was FDA approved in 1997 and voluntarily withdrawn from the United States market in 2008 by the manufacturer for commercial reasons rather than safety concerns. Because it was the active ingredient in a previously approved product, it can be compounded under section 503A when other conditions are met.
The approved product was an injection. A compounded nasal spray is a different route from any that has been approved, and it is not an FDA approved product. We prepare it to a prescriber's specification and make no claim about what it does for a patient. That determination belongs to the prescriber.
We will tell you what we can prepare, what the formulation constraints are, and where a dosage form is a poor fit for a molecule. We will not tell you whether a peptide is appropriate for your patient, what it will do, or what dose to write. Compounded preparations are not FDA approved, they are prepared only against a valid patient specific prescription, and every clinical decision rests with the prescriber. FDA recommends that patients talk with their health care professional about their specific circumstances before taking any medication.
Where peptide compounding stands right now
Peptide compounding is under active regulatory review, and the picture has changed more than once in the past year. Any prescriber writing for a compounded peptide should treat the status as current rather than settled.
FDA maintains interim lists of bulk drug substances nominated for use in compounding under section 503A. Substances in Category 1 are under evaluation and FDA does not intend to act against compounders using them. Substances placed in Category 2 are considered to present significant safety risks and should not be compounded.
In April 2026 FDA announced it would move twelve peptides out of Category 2, a Pharmacy Compounding Advisory Committee meeting was scheduled for July 2026 to review a set of these substances, and a further meeting is expected before the end of February 2027 to consider several more. Removal from Category 2 is not approval, and it does not place a substance on the bulks list.
Because this is moving, call us before writing for any peptide and we will tell you the current position for that specific substance rather than the position as it stood when this page was written.
Thinking about a peptide preparation? Call before you write it and we will tell you honestly what we can and cannot do.
Call (909) 378-7301What this means when you write the prescription
If you send us a peptide troche prescription, expect a call rather than a preparation. We would rather have that conversation than dispense something whose contents we cannot stand behind.
For a nasal preparation, state the peptide, the concentration, the total volume and the directions, and note that a metered spray device is required. Call first if you want to discuss whether the molecule suits the route at all.
Mixwell performs non sterile compounding only. We do not prepare injectables, which rules out the route most peptide products have historically used. If an injectable preparation is what the patient needs, that belongs with a pharmacy licensed for sterile compounding.
Serving prescribers and patients in California
Mixwell Compounding Pharmacy is located in Chino, CA and prepares nasal and mucosal formulations in a purpose built non sterile lab. Patients can collect their preparation at the Chino pharmacy, and delivery is available across California.
- Chino
- Chino Hills
- Ontario
- Rancho Cucamonga
- Upland
- Pomona
- Diamond Bar
- Corona
- Riverside
- Eastvale
- Brea
- Fullerton
Common questions
Why will you not make a peptide troche?
Troches are made by melting a base and stirring the active into it, and polyethylene glycol troche bases melt in a range around 45 to 51 degrees Celsius. Peptides are heat sensitive, and warmth drives unfolding, hydrolysis, oxidation and aggregation. We have no reliable way to know how much intact peptide survives, so we do not dispense the preparation.
Would a peptide troche work if it survived compounding?
It would still face three obstacles. Saliva and oral tissue contain enzymes that break peptide bonds, peptides are large water loving molecules that cross the lining of the mouth poorly, and any saliva swallowed carries drug to a stomach built to digest peptides.
Why a nasal spray instead?
A nasal spray is compounded as a solution at room temperature, so no heating step is involved. The lining of the nose is thin and well supplied with blood vessels, absorption enters the circulation directly, and residence time is short. Peptides delivered nasally are established in approved medicine, with FDA approved peptide nasal sprays including desmopressin and calcitonin salmon.
Is a nasal spray as good as an injection?
No. Nasal bioavailability for peptides is generally much lower than injection, absorption can change when a patient is congested, and very large peptides still cross poorly. Nasal is a better fit than a troche for a peptide, not an equivalent to an injectable.
Is compounded sermorelin FDA approved?
No. Sermorelin acetate was FDA approved in 1997 and voluntarily withdrawn from the United States market in 2008 for commercial reasons rather than safety. Because it was the active ingredient in a previously approved product it can be compounded under section 503A, but a compounded preparation is not FDA approved, and the approved product was an injection rather than a nasal spray.
Can you compound any peptide I ask for?
No. Peptide compounding is under active FDA review and substances placed in Category 2 of the interim bulks list should not be compounded. The position has changed more than once in the past year, so call us with the specific substance and we will tell you where it stands today.
Does Mixwell accept insurance?
Mixwell does not accept insurance. Call (909) 378-7301 to discuss current pricing.
Key Takeaways
- Troches are made by melting a base, and polyethylene glycol troche bases melt around 45 to 51 degrees Celsius, which is a poor environment for a heat sensitive peptide.
- Even an intact peptide faces enzymes in saliva, a mucosal barrier poorly suited to large molecules, and digestion of anything swallowed.
- A nasal spray is compounded at room temperature with no heating step, and peptide nasal delivery is established in approved medicine.
- Nasal delivery is better than a troche for a peptide but is not equivalent to an injection, and Mixwell does not compound injectables.
- Peptide compounding is under active FDA review, so the status of any specific substance should be confirmed before a prescription is written.
Sources
- U.S. Food and Drug Administration. Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act, including the interim policy and category definitions. fda.gov
- U.S. Food and Drug Administration. Pharmacy Compounding Advisory Committee, notice of meeting and request for comments, bulk drug substances nominated for inclusion on the section 503A bulk drug substances list. Federal Register, April 2026.
- University of North Carolina Eshelman School of Pharmacy. Lozenges and medication sticks, compounding laboratory exercises, including troche base selection and melting behaviour. pharmlabs.unc.edu
- Standard pharmaceutics references on peptide and protein stability, including thermal denaturation, hydrolysis, deamidation, oxidation and aggregation.
- U.S. Food and Drug Administration. Desmopressin acetate nasal spray and calcitonin salmon nasal spray prescribing information.
- United States Pharmacopeia. General Chapter 795, Pharmaceutical Compounding, Nonsterile Preparations.