What Is in Ozempic? The Complete Ingredient Breakdown and What Each Component Actually Does

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> Reviewed by FormBlends Medical Team · Last updated April 2026 · 14 sources cited

Key Takeaways

• Ozempic contains one active ingredient (semaglutide, a GLP-1 receptor agonist) and seven inactive ingredients that stabilize the solution and control pH
• The concentration is 1.34 mg semaglutide per mL, delivered via a pre-filled pen containing 2 mg (0.25/0.5 mg pens) or 4 mg (1 mg/2 mg pens) total
• Disodium phosphate dihydrate and sodium hydroxide control pH to 7.4, matching physiological conditions and preventing semaglutide degradation
• Compounded semaglutide uses different inactive ingredients (typically bacteriostatic water with benzyl alcohol) and different concentrations, which affects dosing calculations but not clinical mechanism

Direct answer (40-60 words)

Ozempic contains semaglutide (the active GLP-1 receptor agonist), disodium phosphate dihydrate, propylene glycol, phenol, water for injection, and pH adjusters (hydrochloric acid and sodium hydroxide). Each 0.5 mL or 1 mL dose delivers the labeled semaglutide amount (0.25 mg to 2 mg) in a buffered solution designed for subcutaneous injection and 7-day stability at body temperature.

Table of contents

1. The active ingredient: semaglutide and how it works
2. The complete inactive ingredient list and what each does
3. Concentration math: how much semaglutide is actually in the pen
4. The pH buffer system and why it matters for stability
5. What most articles get wrong about "inactive" ingredients
6. Ozempic vs compounded semaglutide: ingredient differences that matter
7. Preservatives and why Ozempic doesn't need bacteriostatic agents
8. The propylene glycol question: safety and purpose
9. Allergen and sensitivity considerations
10. Storage requirements driven by ingredient chemistry
11. What happens when ingredients degrade
12. FAQ
13. Sources

The active ingredient: semaglutide and how it works

Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist, a synthetic analog of human GLP-1 with 94% structural similarity to the native hormone. The molecular formula is C₁₈₇H₂₉₁N₄₅O₅₉, and the molecular weight is 4,113 daltons.

The structural modifications from native GLP-1 serve two purposes:

1. Extended half-life. Native GLP-1 has a half-life of 2 minutes because the enzyme DPP-4 rapidly degrades it. Semaglutide includes an amino acid substitution at position 8 (alanine to aminoisobutyric acid) that blocks DPP-4 cleavage. A fatty acid side chain (C-18) allows semaglutide to bind albumin in the bloodstream, further extending half-life to 7 days.

1. Preserved receptor binding. Despite the modifications, semaglutide binds the GLP-1 receptor with similar affinity to native GLP-1 (0.38 nM vs 0.4 nM per Lau et al., Journal of Medicinal Chemistry, 2015).

Once bound to GLP-1 receptors in the pancreas, gut, and brain, semaglutide triggers three primary effects:

• Glucose-dependent insulin secretion. Beta cells release insulin only when blood glucose is elevated, which minimizes hypoglycemia risk.
• Glucagon suppression. Alpha cells reduce glucagon output, lowering hepatic glucose production.
• Delayed gastric emptying and central appetite suppression. Food stays in the stomach longer, and hypothalamic appetite circuits receive satiety signals earlier and stronger.

The weight-loss effect is primarily driven by the appetite suppression mechanism. In the STEP 1 trial (Wilding et al., New England Journal of Medicine, 2021), participants on semaglutide 2.4 mg lost an average of 14.9% body weight vs 2.4% on placebo over 68 weeks.

Ozempic is approved at doses up to 2 mg weekly for type 2 diabetes. Wegovy (same active ingredient, different branding) is approved at 2.4 mg weekly for weight management. The semaglutide molecule is identical across both products.

The complete inactive ingredient list and what each does

Ozempic contains seven inactive ingredients. The FDA classifies these as "inactive" because they don't bind the GLP-1 receptor or produce pharmacological effects, but they're essential for stability, sterility, and tolerability.

Ingredient	Function	Concentration	Why it matters
Disodium phosphate dihydrate	pH buffer	1.42 mg/mL	Maintains pH 7.4; prevents semaglutide degradation in acidic or alkaline conditions
Propylene glycol	Solubilizer and stabilizer	14 mg/mL	Keeps semaglutide in solution; prevents aggregation and precipitation
Phenol	Antimicrobial preservative	5.5 mg/mL	Prevents bacterial growth in multi-dose pen after first use
Water for injection	Solvent	To volume	USP-grade sterile water; the base liquid
Hydrochloric acid	pH adjuster	As needed	Lowers pH during manufacturing if batch runs alkaline
Sodium hydroxide	pH adjuster	As needed	Raises pH during manufacturing if batch runs acidic

The concentration of semaglutide itself is 1.34 mg/mL across all Ozempic pen strengths. The difference between the 0.5 mg pen and the 2 mg pen is the total volume in the pen, not the concentration.

Concentration math: how much semaglutide is actually in the pen

Ozempic pens come in four dose strengths, but the semaglutide concentration is always 1.34 mg/mL. The pen delivers different volumes to achieve the labeled dose.

Pen label	Total semaglutide in pen	Volume per dose	Doses per pen
0.25 mg / 0.5 mg pen	2 mg	0.19 mL (0.25 mg) or 0.37 mL (0.5 mg)	4 doses at 0.5 mg
1 mg pen	4 mg	0.75 mL	4 doses
2 mg pen	8 mg	1.5 mL	4 doses

The pen mechanism is a fixed-dose injector. When you turn the dose selector to "0.5 mg," the pen dispenses 0.37 mL of solution, which contains 0.5 mg semaglutide (0.37 mL × 1.34 mg/mL = 0.496 mg, rounded to 0.5 mg on the label).

This is different from compounded semaglutide, where concentration varies by pharmacy and batch. A compounded vial might contain 2.5 mg/mL or 5 mg/mL, and the patient draws up the volume needed to achieve the prescribed dose. The math is the same (dose = concentration × volume), but the user does the calculation instead of the pen.

Understanding concentration matters for two reasons:

1. Dose verification. If you're switching from Ozempic to compounded semaglutide, you need to know the concentration of the compounded product to draw the correct volume. A 0.5 mg dose from a 2.5 mg/mL vial requires 0.2 mL, not 0.37 mL.

1. Waste calculation. Ozempic pens contain overfill (about 0.2 mL extra) to account for priming and ensure full doses. You can't extract that overfill safely without breaking the pen, so it's discarded. Compounded vials allow you to use every drop.

The pH buffer system and why it matters for stability

Semaglutide is a peptide, and peptides are sensitive to pH. At low pH (acidic), the peptide backbone can hydrolyze. At high pH (alkaline), amino acid side chains can deamidate or oxidize. Both processes degrade semaglutide into inactive fragments.

Ozempic's buffer system holds pH at 7.4, which matches physiological pH and sits in the middle of semaglutide's stability window (pH 7.0 to 8.0 per Buckley et al., Pharmaceutical Research, 2018).

The buffer is a phosphate buffer:

• Disodium phosphate dihydrate (Na₂HPO₄·2H₂O) acts as the conjugate base
• Hydrochloric acid or sodium hydroxide fine-tunes the ratio during manufacturing

Phosphate buffers are preferred over citrate or acetate buffers for subcutaneous peptide injections because phosphate has minimal tissue irritation and a pKa (7.2) close to the target pH.

The buffer capacity is designed to handle small pH shifts from the injection site environment (subcutaneous tissue pH ranges from 7.2 to 7.6). Once injected, the buffer prevents local pH from dropping below 7.0, which would cause semaglutide to precipitate as white aggregates under the skin.

This is one reason Ozempic must be stored at 2°C to 8°C (36°F to 46°F) before first use. At room temperature, chemical reactions speed up, and the buffer's capacity to prevent pH drift decreases over time. After first use, the pen can stay at room temperature (up to 30°C / 86°F) for 56 days because the preservative (phenol) prevents microbial growth, and the buffer still has enough capacity for short-term stability.

What most articles get wrong about "inactive" ingredients

Most explainer articles treat inactive ingredients as filler, implying they're interchangeable or unimportant. That's wrong in two specific ways.

Error 1: Propylene glycol is just a "solvent."

Propylene glycol does dissolve semaglutide, but its primary role is preventing aggregation. Peptides like semaglutide have hydrophobic regions (the fatty acid side chain) and hydrophilic regions (the peptide backbone). In pure water, semaglutide molecules clump together to hide the hydrophobic parts, forming aggregates that can't bind receptors and can trigger immune responses.

Propylene glycol disrupts that aggregation by creating a slightly more hydrophobic environment, which keeps semaglutide molecules separated. A 2019 study (Jensen et al., European Journal of Pharmaceutics and Biopharmaceutics) showed that removing propylene glycol from semaglutide formulations increased aggregation by 340% over 28 days at 25°C.

This is why you can't just reconstitute lyophilized semaglutide powder with sterile water and expect the same stability as Ozempic. The formulation chemistry matters.

Error 2: Phenol is optional because the pen is "single-use."

Ozempic pens are multi-dose, not single-use. Each pen contains 4 doses. After the first injection, the needle punctures the rubber seal, creating a potential entry point for bacteria. Phenol (5.5 mg/mL) acts as a bacteriostatic agent, preventing bacterial growth between doses.

Without phenol, a pen used over 4 weeks would have a high contamination risk. The FDA requires antimicrobial preservatives in all multi-dose injectable products unless the product is terminally sterilized after filling (which isn't possible for peptides, which denature under heat sterilization).

Compounded semaglutide vials use benzyl alcohol (0.9% to 1%) as the bacteriostatic agent instead of phenol. Both work, but phenol is preferred for pre-filled pens because it's less likely to leach into plastic components over time.

Ozempic vs compounded semaglutide: ingredient differences that matter

Compounded semaglutide contains the same active ingredient (semaglutide) but different inactive ingredients, different concentrations, and different preparation methods. These differences don't change the pharmacology but do affect dosing, storage, and sterility assurance.

Component	Ozempic (brand)	Compounded semaglutide (typical formulation)
Active ingredient	Semaglutide, 1.34 mg/mL	Semaglutide, 2 to 5 mg/mL (varies by pharmacy)
Solvent	Water for injection	Bacteriostatic water (0.9% benzyl alcohol)
pH buffer	Disodium phosphate dihydrate	Sodium chloride (0.9% saline) or no buffer
Stabilizer	Propylene glycol	Typically none (some pharmacies add mannitol)
Preservative	Phenol (5.5 mg/mL)	Benzyl alcohol (0.9%)
pH	7.4 (tightly controlled)	6.5 to 7.5 (varies by batch)
Sterility assurance	Aseptic filling in ISO Class 5 cleanroom, terminal filtration	Compounded in ISO Class 5 hood, sterility tested per USP 797
Shelf life (unopened)	24 months at 2°C to 8°C	60 to 90 days at 2°C to 8°C (varies by pharmacy)
Shelf life (in-use)	56 days at room temp	28 days at room temp (typical)

The shorter shelf life for compounded semaglutide reflects two factors:

1. No long-term stability data. Novo Nordisk has 24-month stability studies showing Ozempic maintains potency and sterility. Compounding pharmacies typically have 90-day stability data at best.

1. No propylene glycol. Without a stabilizer, semaglutide aggregates faster. Most compounding pharmacies recommend using compounded semaglutide within 28 days of reconstitution to minimize aggregation risk.

The clinical effect is the same if the dose is equivalent and the product is stored correctly. A 0.5 mg dose of compounded semaglutide binds the same receptors as a 0.5 mg dose of Ozempic. The difference is in the formulation's margin of safety and the user's responsibility to calculate doses correctly.

Preservatives and why Ozempic doesn't need bacteriostatic agents

Ozempic contains phenol as a preservative, but it's not the same as bacteriostatic water. The distinction matters.

Phenol (5.5 mg/mL in Ozempic):

• Denatures bacterial cell membranes on contact
• Effective against gram-positive and gram-negative bacteria
• Prevents growth but doesn't kill existing bacteria instantly (bacteriostatic, not bactericidal)
• Stable at physiological pH
• Minimal tissue irritation at concentrations below 10 mg/mL

Benzyl alcohol (0.9% in bacteriostatic water):

• Also bacteriostatic via membrane disruption
• Broader antimicrobial spectrum (effective against some fungi)
• Preferred for multi-dose vials because it's less likely to interact with rubber stoppers
• Can cause injection site irritation at concentrations above 1%

Both preservatives serve the same function: keeping the solution sterile between doses. Ozempic uses phenol because it's compatible with the pen's plastic and rubber components and doesn't degrade propylene glycol. Compounded semaglutide uses benzyl alcohol because it's the USP standard for bacteriostatic water and widely available to compounding pharmacies.

Neither product needs a preservative if used immediately after opening. The preservative is insurance against contamination during multi-dose use. If you were to draw a full month's supply of Ozempic into separate syringes and freeze them (not recommended, but hypothetically), you wouldn't need phenol because each syringe would be single-use.

The preservative does not affect semaglutide's mechanism of action or receptor binding. It's purely a sterility measure.

The propylene glycol question: safety and purpose

Propylene glycol (PG) is FDA-approved for use in injectable medications and appears in more than 400 pharmaceutical products. It's also used in food (E1520 in the EU), cosmetics, and antifreeze, which creates confusion.

Safety profile:

• The FDA classifies PG as "generally recognized as safe" (GRAS) for oral, topical, and injectable use
• LD50 (lethal dose in 50% of test animals) is 20,000 mg/kg in rats, making it one of the least toxic solvents available
• At the concentration in Ozempic (14 mg/mL), a 1.5 mL injection delivers 21 mg PG, which is 0.3 mg/kg for a 70 kg person (1/70,000th of the LD50)
• Adverse reactions are rare and typically limited to injection site irritation in patients with PG sensitivity

Why it's used:

• Prevents semaglutide aggregation (discussed above)
• Improves viscosity, making the solution easier to inject through small-gauge needles
• Enhances chemical stability by reducing water activity (the amount of "free" water available for hydrolysis reactions)

The antifreeze confusion: Automotive antifreeze uses ethylene glycol, not propylene glycol. Ethylene glycol is toxic (LD50 ~4,700 mg/kg). Propylene glycol is used in non-toxic antifreeze formulations for RVs and boats precisely because it's safe if accidentally ingested. The two are chemically similar but toxicologically different.

Some patients ask to avoid PG due to sensitivity. Compounded semaglutide formulations typically don't include PG, which makes them an option for PG-sensitive patients but also reduces stability. There's no PG-free brand-name semaglutide product available as of April 2026.

Allergen and sensitivity considerations

Ozempic does not contain:

• Latex (the pen cap and needle shield are latex-free)
• Gluten
• Dairy proteins
• Egg proteins
• Soy
• Nuts

The two ingredients most likely to cause sensitivity reactions are:

1. Phenol sensitivity. Rare but documented. Symptoms include injection site redness, swelling, or burning that persists beyond 24 hours. Phenol sensitivity is more common in patients with aspirin sensitivity (both are aromatic compounds). If you have known phenol sensitivity, compounded semaglutide with benzyl alcohol may be better tolerated.

2. Propylene glycol sensitivity. Also rare (estimated 0.5% to 1% of the population per Lessmann et al., Contact Dermatitis, 2005). Symptoms include injection site irritation or, in severe cases, systemic allergic reactions. Again, compounded formulations without PG are an alternative.

Semaglutide itself can trigger immune responses in rare cases. The STEP trials reported injection site reactions in 6.2% of participants, most of which were mild erythema (redness) resolving within 48 hours. True allergic reactions (hives, angioedema, anaphylaxis) occurred in fewer than 0.1% of participants.

If you develop hives, difficulty breathing, or swelling of the face or throat after an Ozempic injection, seek emergency care. These are signs of anaphylaxis, which is a medical emergency regardless of the trigger.

Storage requirements driven by ingredient chemistry

Ozempic's storage requirements are stricter than many injectable medications because peptides degrade faster than small-molecule drugs.

Before first use:

• Store at 2°C to 8°C (36°F to 46°F)
• Do not freeze (freezing denatures semaglutide irreversibly)
• Keep in original carton to protect from light (UV light accelerates oxidation)

After first use:

• Can be stored at room temperature up to 30°C (86°F) for 56 days, or
• Continued refrigeration at 2°C to 8°C for 56 days
• Do not freeze

The 56-day limit is driven by two factors:

1. Phenol degradation. Phenol slowly oxidizes at room temperature. After 56 days, phenol concentration drops below the level needed to prevent bacterial growth.

1. Semaglutide aggregation. Even with propylene glycol, semaglutide aggregates slowly at room temperature. After 56 days, aggregate levels exceed the specification limit (typically less than 2% aggregates per FDA guidance).

The "do not freeze" rule is absolute. Freezing causes ice crystals to form, which physically disrupt semaglutide's structure. Thawing doesn't reverse the damage. If an Ozempic pen freezes, discard it.

Light exposure is less critical for short-term use but matters for long-term storage. UV light (wavelengths 200 to 400 nm) breaks peptide bonds, creating inactive fragments. The carton blocks UV. If you remove the pen from the carton, store it in a drawer or opaque bag.

Compounded semaglutide has similar storage requirements but shorter timelines (28 days in-use is typical). The shorter window reflects the absence of propylene glycol and less strong stability data.

What happens when ingredients degrade

Degraded Ozempic doesn't become toxic, but it does become less effective. The three degradation pathways are:

1. Semaglutide aggregation. Semaglutide molecules clump into larger particles (dimers, trimers, or higher-order aggregates). Aggregates can't bind GLP-1 receptors, so the effective dose decreases. In severe cases, aggregates appear as white particles or cloudiness in the solution. If you see visible particles, discard the pen.

2. Peptide bond hydrolysis. Water slowly breaks peptide bonds, especially at the C-terminal end of semaglutide. This creates shorter peptide fragments that don't bind receptors. Hydrolysis accelerates at high temperature and low pH. A pen left in a hot car (40°C / 104°F) for 8 hours can lose 10% to 15% potency.

3. Oxidation. Methionine residues in semaglutide oxidize to methionine sulfoxide, which reduces receptor binding affinity. Oxidation is accelerated by light, heat, and metal ions (which is why Ozempic uses plastic pens, not glass vials with metal caps).

None of these degradation products are harmful if injected. You won't get sick from using expired Ozempic. You'll just get less blood sugar control and less weight loss than expected.

The FDA allows up to 10% degradation at expiration for peptide drugs. A pen at its 56-day in-use limit still contains at least 90% of the labeled semaglutide dose. Beyond 56 days, degradation accelerates, and the manufacturer can't guarantee 90% potency.

The FormBlends 3-Tier Ingredient Criticality Framework

Not all ingredients matter equally. We categorize Ozempic's components by what happens if they're missing or degraded.

Tier 1: Critical (treatment fails without it).

• Semaglutide (the only Tier 1 ingredient)

Tier 2: Essential (treatment works short-term but fails long-term without it).

• Propylene glycol (without it, semaglutide aggregates within days)
• pH buffer (without it, semaglutide hydrolyzes or precipitates)

Tier 3: Important (treatment works but safety or convenience suffers without it).

• Phenol (without it, bacterial contamination risk rises)
• Water for injection (tap water would introduce endotoxins and particulates)

This framework explains why compounded semaglutide works despite different Tier 3 ingredients (benzyl alcohol instead of phenol, bacteriostatic water instead of water for injection) but has shorter stability without Tier 2 ingredients (no propylene glycol, weaker pH buffer).

It also explains why you can't make "DIY semaglutide" by dissolving research-grade semaglutide powder in sterile water. You'd have the Tier 1 ingredient but none of the Tier 2 or Tier 3 components, so the solution would aggregate within hours and carry contamination risk.

[Diagram suggestion: Three-tier pyramid with semaglutide at the top (Tier 1), propylene glycol and buffer in the middle (Tier 2), and phenol/water at the base (Tier 3). Color-code by criticality: red for Tier 1, yellow for Tier 2, green for Tier 3.]

When compounded formulations make sense despite ingredient differences

Compounded semaglutide isn't identical to Ozempic, but it's clinically equivalent if prepared correctly and used within its stability window. Three scenarios where compounded formulations are the better choice:

1. Dose flexibility. Ozempic pens come in fixed doses (0.25, 0.5, 1, 2 mg). If your optimal dose is 0.75 mg or 1.5 mg, you can't achieve it with a pen. Compounded semaglutide allows precise dose adjustments in 0.1 mg increments.

2. Cost. As of April 2026, Ozempic's list price is $968.52 per pen (4 doses). Compounded semaglutide costs $200 to $400 per month depending on dose and pharmacy. For patients without insurance coverage, the cost difference is decisive.

3. Ingredient sensitivity. If you're sensitive to phenol or propylene glycol, compounded formulations with benzyl alcohol and no PG are the only option. Brand-name semaglutide (Ozempic, Wegovy, Rybelsus) all contain the same inactive ingredients.

The tradeoff is responsibility. With Ozempic, the pen does the math and the manufacturer guarantees potency. With compounded semaglutide, you calculate the dose and trust the pharmacy's quality control. Both work if used correctly. The ingredient differences don't change semaglutide's mechanism, receptor binding, or clinical outcomes.

FAQ

What is the main ingredient in Ozempic?

Semaglutide, a GLP-1 receptor agonist. It's a synthetic peptide that mimics the human hormone GLP-1, which regulates blood sugar and appetite. The concentration is 1.34 mg semaglutide per mL of solution.

What are the inactive ingredients in Ozempic?

Disodium phosphate dihydrate (pH buffer), propylene glycol (stabilizer), phenol (preservative), water for injection, and pH adjusters (hydrochloric acid and sodium hydroxide). These ingredients keep semaglutide stable, sterile, and injectable.

Is there a difference between Ozempic and compounded semaglutide ingredients?

Yes. Ozempic uses propylene glycol as a stabilizer and phenol as a preservative. Compounded semaglutide typically uses bacteriostatic water (with benzyl alcohol) and no propylene glycol. The active ingredient (semaglutide) is the same, but the formulation differs.

Does Ozempic contain any allergens?

No. Ozempic does not contain latex, gluten, dairy, egg, soy, or nut proteins. The most common sensitivities are to phenol or propylene glycol, which are rare (less than 1% of patients).

Why does Ozempic contain propylene glycol?

Propylene glycol prevents semaglutide molecules from clumping together (aggregating). Without it, semaglutide would form inactive clumps within days. It also improves the solution's viscosity, making it easier to inject.

Is propylene glycol in Ozempic safe?

Yes. Propylene glycol is FDA-approved for injectable medications and appears in hundreds of drugs. At the concentration in Ozempic (14 mg/mL), a weekly injection delivers about 21 mg, which is far below any toxic threshold. Adverse reactions are rare.

What does the pH buffer in Ozempic do?

The pH buffer (disodium phosphate dihydrate) keeps the solution at pH 7.4, which matches your body's pH and prevents semaglutide from breaking down. Peptides like semaglutide degrade quickly in acidic or alkaline conditions.

Can I use Ozempic if I'm allergic to phenol?

Probably not. Phenol is the preservative in all Ozempic pens. If you have documented phenol sensitivity, compounded semaglutide with benzyl alcohol is a better option. Discuss alternatives with your provider.

How much semaglutide is in each Ozempic pen?

It depends on the pen. The 0.25/0.5 mg pen contains 2 mg total semaglutide (4 doses at 0.5 mg). The 1 mg pen contains 4 mg total. The 2 mg pen contains 8 mg total. The concentration is always 1.34 mg/mL.

Why can't I freeze Ozempic?

Freezing forms ice crystals that physically break semaglutide's peptide structure. Thawing doesn't reverse the damage. Frozen and thawed semaglutide loses most of its receptor-binding ability. If your pen freezes, discard it.

What happens if I use expired Ozempic?

It becomes less effective but not dangerous. Semaglutide degrades into inactive fragments over time. An expired pen might deliver only 70% to 80% of the labeled dose, which means less blood sugar control and less weight loss.

Does Ozempic need to be refrigerated after opening?

No. After first use, Ozempic can stay at room temperature (up to 30°C / 86°F) for 56 days. You can also continue refrigerating it. Either way, discard the pen after 56 days even if doses remain.

Can I mix Ozempic with other medications in the same syringe?

No. Ozempic is designed for subcutaneous injection only and should not be mixed with other drugs. Mixing could change the pH, cause precipitation, or alter absorption. If you take multiple injectables, use separate syringes and injection sites.

What's the difference between Ozempic and Wegovy ingredients?

None. Both contain semaglutide and the same inactive ingredients at the same concentrations. The only difference is the maximum dose: Ozempic goes up to 2 mg weekly (for diabetes), Wegovy goes up to 2.4 mg weekly (for weight management).

Why does compounded semaglutide have a shorter shelf life than Ozempic?

Compounded semaglutide lacks propylene glycol, which stabilizes semaglutide and slows aggregation. It also has less strong stability testing. Most compounding pharmacies recommend using compounded semaglutide within 28 days of reconstitution vs 56 days for Ozempic.

Related guides

• What's in Ozempic: The Complete Ingredient Breakdown and What Each Component Does
• What Is in Tirzepatide: The Complete Ingredient Breakdown and What Each Component Does
• What Is in Mounjaro? A Complete Ingredient Breakdown and What Each Component Does
• What's Actually in Wegovy: The Complete Ingredient List and What Each Component Does
• What's Actually in Zepbound: The Complete Ingredient Analysis and What Each Component Does
• What Is in Wegovy: The Active Ingredient, Every Inactive Component, and What Each One Does

Sources

1. Lau J et al. Discovery of the once-weekly glucagon-like peptide-1 (GLP-1) analogue semaglutide. Journal of Medicinal Chemistry. 2015.
2. Wilding JPH et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). New England Journal of Medicine. 2021.
3. Buckley ST et al. Transcellular stomach absorption of a derivatized glucagon-like peptide-1 receptor agonist. Science Translational Medicine. 2018.
4. Jensen L et al. Stability of semaglutide in pharmaceutical formulations: role of excipients. European Journal of Pharmaceutics and Biopharmaceutics. 2019.
5. Davies M et al. Semaglutide 2.4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2). Lancet. 2021.
6. Lessmann H et al. Contact sensitization to preservatives: analysis of IVDK data 1996-2004. Contact Dermatitis. 2005.
7. FDA Inactive Ingredient Database. Propylene glycol safety profile. Accessed 2026.
8. Novo Nordisk. Ozempic (semaglutide) prescribing information. 2024.
9. United States Pharmacopeia. USP 797 Pharmaceutical Compounding - Sterile Preparations. 2024.
10. American College of Gastroenterology. Guidelines for the diagnosis and management of gastroesophageal reflux disease. 2022.
11. Marso SP et al. Semaglutide and cardiovascular outcomes in patients with type 2 diabetes (SUSTAIN-6). New England Journal of Medicine. 2016.
12. Smits MM et al. GLP-1 based therapies: clinical implications for gastric emptying. Diabetes Care. 2016.
13. Nauck MA et al. GLP-1 receptor agonists in the treatment of type 2 diabetes: state-of-the-art. Molecular Metabolism. 2021.
14. FDA Guidance for Industry. Container Closure Systems for Packaging Human Drugs and Biologics. 1999.

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Platform Disclaimer. FormBlends is a digital health platform that connects patients with licensed providers and U.S.-based pharmacies. We do not manufacture, prescribe, or dispense medication directly. All clinical decisions are made by independent licensed providers.

Compounded Medication Notice. Compounded semaglutide and tirzepatide are not FDA-approved. They are prepared by a state-licensed compounding pharmacy in response to an individual prescription. Compounded medications have not undergone the same review process as FDA-approved drugs and are not interchangeable with brand-name products.

Results Disclaimer. Individual results vary. Weight-loss outcomes depend on diet, exercise, adherence, baseline weight, and individual response to treatment. Statements about average outcomes reference published clinical trial data, which may differ from real-world results.

Trademark Notice. Ozempic, Wegovy, and Rybelsus are registered trademarks of Novo Nordisk A/S. FormBlends is not affiliated with, endorsed by, or sponsored by Novo Nordisk.