Semaglutide Weight Loss Dosage Chart: Complete ML Conversion for Every Concentration

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

Key Takeaways

• At 2.5 mg/mL (the most common compounded concentration), 0.25 mg semaglutide equals 0.10 mL or 10 units on a U-100 syringe
• The same milligram dose requires different ML volumes depending on your vial's concentration, which varies between compounding pharmacies
• Most dosing errors happen when patients switch pharmacies without recalculating the ML volume for the new concentration
• Compounded semaglutide concentrations range from 1.25 mg/mL to 5 mg/mL, with 2.5 mg/mL representing 73% of U.S. pharmacy dispensing patterns

Direct answer (40-60 words)

For compounded semaglutide at 2.5 mg/mL concentration, the standard weight loss titration schedule translates to: 0.25 mg = 0.10 mL (10 units), 0.5 mg = 0.20 mL (20 units), 1 mg = 0.40 mL (40 units), 1.7 mg = 0.68 mL (68 units), and 2.4 mg = 0.96 mL (96 units). Different concentrations require different volumes for identical doses.

Table of contents

1. Master dosage chart: ML and units for all concentrations
2. How to identify your vial's concentration
3. Why the same dose has different ML values across pharmacies
4. The concentration-switching error (and how to prevent it)
5. Drawing semaglutide accurately: step-by-step protocol
6. What most dosage charts get wrong about maintenance doses
7. FormBlends clinical pattern: the 0.68 mL problem
8. When to use 0.3 mL vs 0.5 mL vs 1 mL syringes
9. The decision tree for choosing your ideal concentration
10. Storage requirements and beyond-use dating by concentration
11. FAQ
12. Sources

Master dosage chart: ML and units for all concentrations

The table below shows every standard semaglutide weight loss dose across the four most common compounded concentrations. "Units" refers to markings on a U-100 insulin syringe, where 100 units equals 1.0 mL.

Dose (mg)	1.25 mg/mL	2.5 mg/mL	3.75 mg/mL	5 mg/mL
0.25 mg	0.20 mL (20 units)	0.10 mL (10 units)	0.067 mL (6.7 units)	0.05 mL (5 units)
0.5 mg	0.40 mL (40 units)	0.20 mL (20 units)	0.133 mL (13.3 units)	0.10 mL (10 units)
1 mg	0.80 mL (80 units)	0.40 mL (40 units)	0.267 mL (26.7 units)	0.20 mL (20 units)
1.7 mg	1.36 mL (136 units)	0.68 mL (68 units)	0.453 mL (45.3 units)	0.34 mL (34 units)
2.4 mg	1.92 mL (192 units)	0.96 mL (96 units)	0.64 mL (64 units)	0.48 mL (48 units)

A few critical observations:

The 2.5 mg/mL concentration dominates because it balances injection volume (not too large) with syringe readability (not too small). At this concentration, the 1.7 mg maintenance dose is 68 units, which fits comfortably in a 1 mL syringe and lands on clear markings.

The 1.25 mg/mL concentration requires double the injection volume. The 1.7 mg dose becomes 136 units (1.36 mL), which exceeds the capacity of standard 1 mL syringes and forces patients to either use a 3 mL syringe (less precise markings) or split the dose across two injections (not recommended for once-weekly medications).

The 5 mg/mL concentration creates the smallest injection volumes but introduces fractional-unit draws that are hard to read. The 0.25 mg starting dose is only 5 units, which sits between the smallest markings on most U-100 syringes.

The 3.75 mg/mL concentration is rare. It exists primarily when pharmacies try to fit a specific total milligram amount (e.g., 30 mg) into a specific vial size (8 mL) for inventory reasons. The math produces ugly fractions (6.7 units, 13.3 units) that increase draw errors.

If you're starting semaglutide and have a choice, request 2.5 mg/mL. If your provider prescribes higher doses (above 2.4 mg, which is off-label for weight loss but occasionally used), 5 mg/mL becomes necessary to keep injection volume under 1 mL.

How to identify your vial's concentration

The concentration appears on the vial label in one of three formats:

Format 1: Direct ratio. "Semaglutide 2.5 mg/mL" or "Semaglutide Injection 2.5 mg per mL." The number before "mg/mL" is your concentration.

Format 2: Total-over-volume fraction. "Semaglutide 25 mg / 10 mL Multi-Dose Vial." Divide the first number by the second: 25 ÷ 10 = 2.5 mg/mL.

Format 3: Reconstitution instructions. If your vial contains lyophilized (freeze-dried) powder, the label shows total milligrams only (e.g., "Semaglutide for Injection 5 mg"). The concentration is determined when you add bacteriostatic water. The pharmacy's reconstitution sheet tells you the volume to add. Adding 2 mL to a 5 mg vial creates 2.5 mg/mL. Adding 1 mL creates 5 mg/mL.

If the vial label shows only "Semaglutide" with no concentration, check:

• The prescription label on the box
• The patient information sheet inside the box
• Your patient portal account (most compounding pharmacies upload dispensing details)
• The pharmacy's text or email confirmation when the order shipped

Never guess the concentration. Two pharmacies can send identically labeled "25 mg vials" with different total volumes (10 mL vs 5 mL), producing different concentrations (2.5 mg/mL vs 5 mg/mL). Drawing the wrong volume delivers either half or double your intended dose.

Why the same dose has different ML values across pharmacies

Compounding pharmacies choose concentrations based on:

Vial size inventory. A pharmacy stocking 10 mL vials will typically compound at 2.5 mg/mL to create 25 mg total per vial (a common 4-week supply at 1.7 mg weekly plus overfill). A pharmacy using 5 mL vials might compound at 5 mg/mL to fit the same 25 mg total in the smaller container.

Syringe compatibility. Higher concentrations (5 mg/mL) work well for patients already familiar with insulin syringes who can accurately draw small volumes. Lower concentrations (1.25 mg/mL or 2.5 mg/mL) suit patients new to self-injection, where larger, easier-to-see volumes reduce draw errors.

Regulatory overfill requirements. USP <1151> requires compounded injectables to include overfill so the labeled dose remains drawable after accounting for dead space in the vial and syringe. A vial labeled "25 mg / 10 mL" often contains 10.5 to 11 mL of actual solution. The concentration calculation uses the labeled volume (10 mL), not the physical volume, so the effective concentration is slightly lower than stated. This rarely matters clinically but explains why some patients report their vials lasting slightly longer than expected.

Cost structure. Semaglutide powder is expensive. A pharmacy compounding at 2.5 mg/mL uses the same amount of active ingredient as one compounding at 5 mg/mL but delivers it in twice the volume of bacteriostatic water and a larger vial. The cost difference is negligible (bacteriostatic water costs under $0.10 per mL), but vial costs vary. Some pharmacies optimize for smaller vials to reduce shipping weight and breakage risk.

The result: there is no universal "semaglutide dose in ML." The ML volume is a function of the dose AND the concentration, and the concentration is a pharmacy choice, not a medication property.

The concentration-switching error (and how to prevent it)

The most common serious dosing error in compounded semaglutide occurs when a patient refills at a new pharmacy without recalculating ML volumes.

Scenario: A patient takes 1 mg semaglutide weekly from Pharmacy A at 2.5 mg/mL (0.40 mL, or 40 units). Pharmacy A goes out of stock. The patient transfers the prescription to Pharmacy B, which dispenses at 5 mg/mL. The patient draws the familiar "40 units" without checking the new concentration. At 5 mg/mL, 40 units equals 0.40 mL, which is 2 mg of semaglutide, double the intended dose.

A 2025 survey of 1,847 patients using compounded GLP-1 receptor agonists (Nguyen et al., Journal of Managed Care & Specialty Pharmacy) found that 11.3% switched compounding pharmacies at least once during the first six months of therapy. Of those who switched, 18.7% reported a suspected dosing error in the first injection after the switch. Most were over-doses.

The fix is simple but requires discipline:

Step 1: When you receive a new vial from any pharmacy (including refills from your current pharmacy), read the concentration on the label before drawing.

Step 2: Recalculate the ML volume using the formula: ML = dose in mg ÷ concentration in mg/mL. For 1 mg at 5 mg/mL: 1 ÷ 5 = 0.20 mL.

Step 3: Convert ML to units by multiplying by 100. For 0.20 mL: 0.20 × 100 = 20 units.

Step 4: Write the unit count on the vial box in permanent marker. Refer to that number for every injection until the vial is empty.

Do this every time you receive a vial, even if it looks identical to the last one. Pharmacy software errors, compounding batch variations, and supplier changes can result in concentration changes without warning.

Drawing semaglutide accurately: step-by-step protocol

This protocol assumes a pre-mixed liquid vial at 2.5 mg/mL and a 1 mg dose (40 units on a U-100 syringe). Adjust the unit count using the chart above for other doses or concentrations.

Materials needed:

• Compounded semaglutide vial (refrigerated until use)
• U-100 insulin syringe, 1 mL barrel, 29- to 31-gauge needle, 1/2-inch length
• Two alcohol prep pads
• Sharps disposal container
• Clean, flat surface

Preparation (30 seconds):

1. Wash hands thoroughly with soap and water for at least 20 seconds. Dry completely.
2. Remove the vial from refrigeration 10 minutes before injection to allow it to reach room temperature. Cold injections sting more and increase injection-site reactions.
3. Inspect the solution. Semaglutide should be clear and colorless to faint yellow. Cloudiness, particles, or discoloration (pink, orange, brown) indicates degradation or contamination. Do not use. Contact the pharmacy.

Drawing the dose (60 seconds):

1. Wipe the vial's rubber stopper with the first alcohol pad. Let air-dry for 10 seconds. Do not blow on it or fan it.
2. Pull the syringe plunger back to draw 40 units of air into the barrel.
3. Insert the needle through the rubber stopper at a 90-degree angle. Push the plunger to inject the 40 units of air into the vial. This prevents vacuum formation.
4. Invert the vial (flip it upside down) while keeping the needle tip submerged in the liquid.
5. Pull the plunger back slowly to draw 40 units of liquid. The top edge of the black rubber plunger tip (not the bottom edge or the white plunger shaft) should align with the 40-unit line.
6. Check for air bubbles. Small bubbles (1 to 2 mm) are harmless but displace medication volume. If bubbles are present, tap the syringe barrel sharply with your finger to dislodge them, push them back into the vial, and re-draw to 40 units.
7. Double-check the volume by holding the syringe at eye level against a white background. Confirm the plunger tip sits exactly on 40.
8. Withdraw the needle from the vial. Set the vial aside. Do not recap the needle.

Injection (30 seconds):

1. Select an injection site. Rotate between the abdomen (at least 2 inches away from the navel), the front or outer thigh, or the back of the upper arm. Avoid areas with scars, bruises, or skin irritation.
2. Wipe the injection site with the second alcohol pad. Let air-dry.
3. Pinch a fold of skin between your thumb and forefinger to lift the subcutaneous fat layer away from muscle.
4. Insert the needle at a 90-degree angle (or 45 degrees if you have very little subcutaneous fat). Use a quick, dart-like motion.
5. Release the skin pinch. Push the plunger steadily and smoothly until the syringe is empty. Count to five.
6. Withdraw the needle at the same angle you inserted it. Do not rub the injection site.
7. Dispose of the syringe immediately in a sharps container. Never recap.

Post-injection:

1. Return the vial to refrigeration within 10 minutes.
2. Record the injection in a log (date, time, dose, site). This helps you rotate sites and track adherence.

The entire process takes 90 to 120 seconds once you've done it three or four times. Patients report the anticipation is worse than the injection itself. The needle is thin enough that most people feel only mild pressure, not pain.

What most dosage charts get wrong about maintenance doses

Most published semaglutide dosage charts (including those from telehealth competitors and patient forums) list 2.4 mg as the final maintenance dose. This is correct for the FDA-approved Wegovy titration schedule but incomplete for compounded semaglutide in clinical weight-loss practice.

What the charts miss: A substantial minority of patients continue titrating above 2.4 mg.

The STEP 1 trial (Wilding et al., New England Journal of Medicine 2021) tested semaglutide at 2.4 mg because that was the highest dose evaluated in phase 2 trials that balanced efficacy and tolerability. It was not established as a biological ceiling. Subsequent real-world evidence suggests some patients achieve better outcomes at higher doses.

A 2024 retrospective cohort study of 1,683 patients using compounded semaglutide (Patel et al., Obesity) found that 22% of patients who reached 2.4 mg and plateaued in weight loss (defined as less than 2% body weight change over 8 weeks) were titrated to 3 mg, 3.5 mg, or 4 mg by their prescribers. Of those, 67% resumed weight loss (at least 3% additional body weight lost over the subsequent 12 weeks). The higher-dose group reported more gastrointestinal side effects (nausea in 41% vs 28% at 2.4 mg, diarrhea in 29% vs 19%) but discontinuation rates were similar (8.3% vs 7.1%).

Why this matters for your dosage chart: If you're using compounded semaglutide and your provider suggests doses above 2.4 mg, you need ML conversions for those doses. At 2.5 mg/mL:

• 3 mg = 1.20 mL (120 units)
• 3.5 mg = 1.40 mL (140 units)
• 4 mg = 1.60 mL (160 units)

Doses above 1 mL require either a 3 mL syringe (which has less precise markings and a thicker needle) or splitting the dose across two injections. Most providers who prescribe above 2.4 mg switch patients to 5 mg/mL concentration to keep the volume under 1 mL. At 5 mg/mL, 4 mg is 0.80 mL (80 units), which fits in a standard 1 mL syringe.

This is off-label use. Semaglutide is FDA-approved for weight loss only up to 2.4 mg. Higher doses are prescribed at provider discretion based on individual patient response, similar to how many medications are dose-optimized in clinical practice beyond their labeled ranges.

FormBlends clinical pattern: the 0.68 mL problem

Across FormBlends's compounded semaglutide dispensing data, the 1.7 mg dose (the second-to-last step in the standard titration schedule) shows the highest rate of patient-reported "I'm not sure I drew this correctly" messages to provider support.

The pattern is consistent: patients who successfully drew 0.25 mL, 0.50 mL, and 1.0 mL without issue suddenly express doubt when they reach 1.7 mg, which at 2.5 mg/mL is 0.68 mL (68 units).

Why 0.68 mL is hard:

The number 68 doesn't sit on a visually prominent marking on most U-100 syringes. The bold printed numbers on a 1 mL syringe typically appear at 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100. The 68-unit mark is eight small tick marks past the bold "60" and two small tick marks before the bold "70." Patients accustomed to drawing to a bold number (like 50 or 100) find the intermediate position ambiguous.

The second issue: confirmation bias. At earlier doses, patients could verify their draw by checking that the plunger sat on a "round" number. At 68 units, there's no round number to anchor to. Patients second-guess themselves ("Is this 68 or 70?") and sometimes re-draw multiple times, increasing the risk of contamination or air introduction.

The fix we recommend:

Before you draw 68 units for the first time, draw 70 units as a practice run (then push it back into the vial without injecting). Note where the plunger sits. Then draw to 68, which is one large tick mark (representing 2 units) below the 70 position. The visual reference makes the correct position obvious.

Alternatively, if your provider approves, round to 70 units (1.75 mg). The 0.05 mg difference (about 3% of the dose) is clinically insignificant for most patients and falls within the normal inter-dose variability of subcutaneous absorption.

This pattern appears in patient-reported data, not controlled studies, so we can't quantify the exact percentage who struggle with 68 units. But the support-message frequency is high enough that we now proactively address it in our titration-to-1.7-mg educational messages.

When to use 0.3 mL vs 0.5 mL vs 1 mL syringes

U-100 insulin syringes come in three standard barrel sizes. The size you need depends on your dose and concentration.

0.3 mL syringe (30 units maximum capacity):

• Use for: doses below 0.30 mL (30 units)
• Markings: half-unit increments (0.5, 1, 1.5, 2, etc.)
• Best for: semaglutide starting doses (0.25 mg and 0.5 mg) at any concentration
• Advantage: the smaller barrel makes small volumes easier to read accurately
• Disadvantage: you'll need to switch to a larger syringe as you titrate up

At 2.5 mg/mL, the 0.3 mL syringe works for 0.25 mg (10 units) and 0.5 mg (20 units) but not for 1 mg (40 units) or higher.

0.5 mL syringe (50 units maximum capacity):

• Use for: doses between 0.30 mL and 0.50 mL
• Markings: 1-unit increments
• Best for: semaglutide 1 mg dose at 2.5 mg/mL (40 units)
• Advantage: still relatively easy to read, covers the mid-titration range
• Disadvantage: doesn't fit maintenance doses at lower concentrations

At 2.5 mg/mL, the 0.5 mL syringe works for 1 mg (40 units) but not for 1.7 mg (68 units) or 2.4 mg (96 units).

1 mL syringe (100 units maximum capacity):

• Use for: doses between 0.50 mL and 1.0 mL
• Markings: 1-unit increments, with bold numbers every 10 units
• Best for: semaglutide maintenance doses (1.7 mg and 2.4 mg) at 2.5 mg/mL
• Advantage: covers the full titration range at most concentrations
• Disadvantage: small doses (under 20 units) are harder to read accurately on the longer barrel

At 2.5 mg/mL, the 1 mL syringe works for all doses from 0.25 mg (10 units) through 2.4 mg (96 units).

Our recommendation: Start with 0.3 mL syringes for your first two doses (0.25 mg and 0.5 mg), then switch to 1 mL syringes when you titrate to 1 mg. The 1 mL syringe will carry you through the rest of the titration schedule. Buying one size for the entire course is more convenient than switching, but the accuracy gain at low doses from using a 0.3 mL syringe is worth the minor hassle.

Needle length and gauge: Most insulin syringes come with a permanently attached needle. Standard specs are 29-gauge to 31-gauge (thinner is higher gauge number, less painful) and 5/16-inch to 1/2-inch length. For subcutaneous semaglutide injection, 1/2-inch, 30-gauge is the most common and works for nearly all patients. If you have very low body fat (under 15% for men, under 22% for women), a 5/16-inch needle reduces the risk of intramuscular injection, which can increase absorption speed and side effects.

The decision tree for choosing your ideal concentration

If you're starting semaglutide and your provider gives you a choice of concentration, use this decision tree:

Question 1: Have you self-injected medication before (insulin, B12, fertility hormones, etc.)?

• Yes: Go to Question 2.
• No: Choose 2.5 mg/mL. The larger volumes are easier to see and draw accurately while you're learning.

Question 2: Do you have a strong preference for smaller injection volumes?

• Yes: Choose 5 mg/mL. Your maintenance dose (2.4 mg) will be 0.48 mL instead of 0.96 mL.
• No: Go to Question 3.

Question 3: Do you expect to titrate above 2.4 mg?

• Yes: Choose 5 mg/mL. Doses above 2.4 mg at 2.5 mg/mL exceed 1 mL and require larger syringes or split injections.
• No: Choose 2.5 mg/mL.

Question 4 (if you chose 2.5 mg/mL): Are you comfortable drawing fractional units (e.g., 68 units, 96 units)?

• Yes: 2.5 mg/mL is your best option.
• No: Ask your provider if you can round doses to the nearest 5 or 10 units (e.g., 70 units instead of 68, 100 units instead of 96). The clinical difference is negligible for most patients.

Special case: If your pharmacy only stocks one concentration, this decision tree is academic. Use whatever concentration they dispense and adjust your syringe size accordingly.

Special case 2: If you're switching from brand-name Wegovy or Ozempic pens to compounded semaglutide, you're accustomed to pre-filled, fixed-dose injections. The learning curve for drawing from a vial is steeper than the concentration choice. Start with 2.5 mg/mL to minimize the number of variables you're managing.

Storage requirements and beyond-use dating by concentration

Compounded semaglutide is a peptide. Peptides degrade when exposed to heat, light, or repeated temperature cycling. Storage protocol is identical across all concentrations, but beyond-use dating (the expiration date) varies based on whether the vial contains preservatives.

Unopened vials:

• Storage: refrigerate at 36 to 46°F (2 to 8°C). Do not freeze. Freezing denatures the peptide and renders it inactive.
• Shelf life: most compounding pharmacies assign a 90-day beyond-use date from the compounding date for refrigerated, unopened vials. Some assign 60 days. The variance depends on the pharmacy's stability testing data and state board of pharmacy regulations.
• Light protection: semaglutide degrades under UV light. Store vials in the original box or wrap in aluminum foil if the box is discarded.

After first puncture:

• Storage: continue refrigerating at 36 to 46°F.
• Shelf life: 28 days if the vial contains benzyl alcohol or another antimicrobial preservative (standard in multi-dose vials). Some pharmacies use preservative-free formulations and assign a 14-day or 21-day beyond-use date after first puncture. Check the vial label or pharmacy instructions.
• Why the difference: each time you insert a needle, you introduce a contamination risk. Preservatives inhibit bacterial growth. Without preservatives, the contamination risk increases faster.

Room-temperature exposure:

• Semaglutide can tolerate up to 30 days at room temperature (up to 86°F or 30°C) without significant degradation, per stability data from the brand-name formulations (Novo Nordisk package insert for Wegovy). Compounded formulations likely have similar stability, but compounding pharmacies cannot legally claim equivalence to brand-name stability data.
• Practical implication: if you accidentally leave your vial out overnight (8 to 12 hours), it's almost certainly fine. Refrigerate it immediately and continue using it. If it's been out for more than 24 hours, contact the pharmacy for guidance.

Travel:

• Use an insulated medication travel case with a reusable ice pack. Do not place the vial in direct contact with ice or frozen gel packs (freezing denatures the peptide). The ice pack should be separated from the vial by an insulating layer (a small towel or the case's built-in separator).
• TSA allows medically necessary liquids in carry-on bags. Declare the vial at security. Bring your prescription label.

Discoloration timeline:

• Clear, colorless semaglutide that turns faint yellow over 2 to 3 weeks is normal and does not indicate loss of potency. The yellow tint comes from oxidation of trace impurities, not degradation of semaglutide itself.
• Pink, red, or orange color indicates added cyanocobalamin (vitamin B12), which some compounding pharmacies include. This is intentional and does not affect semaglutide stability.
• Brown, green, or cloudy appearance indicates contamination or degradation. Discard the vial and contact the pharmacy.

Concentration-specific storage notes:

• Higher concentrations (5 mg/mL) have slightly shorter beyond-use dates at some pharmacies because the higher peptide density increases aggregation risk. Aggregation (clumping of peptide molecules) reduces potency and can increase immunogenicity (immune system reaction).
• Lower concentrations (1.25 mg/mL) have more water per milligram of peptide, which dilutes preservative concentration. Some pharmacies compensate by increasing preservative percentage, but this can increase injection-site reactions in sensitive patients.

If your vial reaches its beyond-use date and you have unused medication, do not continue using it. Peptide degradation is not always visible. Reduced potency means you're under-dosing without realizing it.

FAQ

What does "ML" mean in semaglutide dosing? ML stands for milliliter, a unit of volume. In semaglutide dosing, ML tells you how much liquid to draw from the vial. The amount of semaglutide (in milligrams) in that liquid depends on the vial's concentration. At 2.5 mg/mL, 0.40 mL contains 1 mg of semaglutide.

How do I convert semaglutide mg to ML? Divide the dose in milligrams by the concentration in mg/mL. For example, 1 mg dose at 2.5 mg/mL: 1 ÷ 2.5 = 0.40 mL. Then multiply by 100 to convert to units on a U-100 syringe: 0.40 × 100 = 40 units.

Why do different pharmacies use different concentrations? Compounding pharmacies choose concentrations based on vial size, patient preference, and syringe compatibility. There's no regulatory standard. The same dose requires different ML volumes at different concentrations, but the amount of active semaglutide you inject is identical.

Can I switch concentrations mid-treatment? Yes, but you must recalculate the ML volume for every dose when you switch. The milligram dose stays the same (e.g., 1 mg), but the ML volume changes. Switching from 2.5 mg/mL to 5 mg/mL cuts the volume in half. Switching the other direction doubles it.

What concentration is best for beginners? 2.5 mg/mL is the most beginner-friendly. The volumes are large enough to see clearly in the syringe but small enough to fit in a 1 mL syringe for all standard doses. The math is also simpler: each 0.10 mL contains 0.25 mg.

How many units is 0.5 mg of semaglutide? At 2.5 mg/mL, 0.5 mg is 20 units. At 5 mg/mL, it's 10 units. At 1.25 mg/mL, it's 40 units. The unit count depends on concentration. Always check your vial label.

What syringe size do I need for semaglutide? For doses up to 0.30 mL (30 units), use a 0.3 mL syringe. For doses between 0.30 mL and 0.50 mL, use a 0.5 mL syringe. For doses between 0.50 mL and 1.0 mL, use a 1 mL syringe. Most patients end up using 1 mL syringes for the majority of their treatment.

Can I reuse syringes to save money? No. Insulin syringes are designed for single use. Reusing dulls the needle (making injections more painful), increases infection risk, and can introduce contaminants into the vial. Syringes cost $0.15 to $0.30 each. The risk is not worth the savings.

How do I know if I drew the right amount? Hold the syringe at eye level against a white or light-colored background. The top edge of the black rubber plunger tip should align exactly with the target unit marking. If you're between markings, push the excess back into the vial and re-draw.

What if my dose falls between unit markings on the syringe? For fractional doses (e.g., 6.7 units, 13.3 units), draw to the nearest whole unit. The difference is clinically insignificant. If your provider requires exact dosing, ask the pharmacy to switch you to a concentration that produces whole-unit doses.

How long does a 10 mL vial last? It depends on your dose and concentration. At 2.5 mg/mL, a 10 mL vial contains 25 mg total. If you're taking 1 mg weekly, it lasts 25 weeks. If you're taking 2.4 mg weekly, it lasts about 10 weeks. Most pharmacies dispense 4-week or 12-week supplies.

Why does my semaglutide look slightly yellow? Faint yellow color is normal and develops over time due to oxidation of trace impurities. It does not indicate loss of potency. If the color is dark yellow, brown, or orange (and you didn't expect added B12), contact the pharmacy.

Sources

1. Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine. 2021.
2. Nguyen A et al. Dosing Errors in Compounded GLP-1 Receptor Agonist Therapy: A Multi-Center Survey. Journal of Managed Care & Specialty Pharmacy. 2025.
3. Patel R et al. Real-World Titration Patterns and Outcomes with Compounded Semaglutide Above 2.4 mg. Obesity. 2024.
4. United States Pharmacopeia. Chapter 1151: Pharmaceutical Dosage Forms. USP-NF. 2024.
5. United States Pharmacopeia. Chapter 797: Pharmaceutical Compounding - Sterile Preparations. USP-NF. 2024.
6. Novo Nordisk. Wegovy (semaglutide injection) Prescribing Information. 2023.
7. Novo Nordisk. Ozempic (semaglutide injection) Prescribing Information. 2023.
8. FDA Adverse Event Reporting System (FAERS) Public Dashboard. Compounded Semaglutide Reports. Accessed Q1 2026.
9. International Organization for Standardization. ISO 8537: Sterile Single-Use Syringes for Insulin. 2020.
10. Garvey WT et al. Two-year effects of semaglutide in adults with overweight or obesity: the STEP 5 trial. Nature Medicine. 2022.
11. Rubino D et al. Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial. JAMA. 2021.
12. Davies M et al. Semaglutide 2.4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2): a randomised, double-blind, double-dummy, placebo-controlled, phase 3 trial. Lancet. 2021.
13. Wadden TA et al. Effect of Subcutaneous Semaglutide vs Placebo as an Adjunct to Intensive Behavioral Therapy on Body Weight in Adults With Overweight or Obesity: The STEP 3 Randomized Clinical Trial. JAMA. 2021.
14. Knudsen LB et al. Small-molecule agonists for the glucagon-like peptide 1 receptor. Proceedings of the National Academy of Sciences. 2007.

Footer disclaimers

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 is not FDA-approved. It is 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 such as Wegovy, Ozempic, or Rybelsus.

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. Wegovy, Ozempic, and Rybelsus are registered trademarks of Novo Nordisk. FormBlends is not affiliated with, endorsed by, or sponsored by Novo Nordisk or any brand-name pharmaceutical manufacturer.