How to Inject Semaglutide: Step-by-Step Guide

Summary: Semaglutide is injected subcutaneously once a week into the abdomen, thigh, or upper outer arm. Brand pens like Ozempic and Wegovy click the dose in for you. Compounded vials require an insulin syringe, the correct unit mark, and a calm 90-degree push.

This content is for informational purposes only and is not medical advice. Always consult a qualified healthcare provider before starting, changing, or stopping any medication.

Semaglutide goes under the skin, not into a muscle, not into a vein. Once a week, same day each week, into the abdomen, the front of the thigh, or the upper outer arm. With a brand pen (Ozempic or Wegovy) you attach a needle, dial the dose if your pen lets you, press the button, and hold for six seconds. With a compounded vial you draw to the unit mark your pharmacy printed on the label, insert at 90 degrees, push slow, and pull out. That is the whole procedure. The details below are what stop the procedure from going sideways.

Before your first injection

Three checks before you uncap anything:

1. The label. Confirm the medication name, the strength, and the expiration date. If you are on a compounded vial, the concentration in mg/mL is the most important number on that label. Drawing 25 units from a 2.5 mg/mL vial is a different dose than 25 units from a 5 mg/mL vial.
2. The temperature. An unopened Ozempic or Wegovy pen lives in the fridge at 36 to 46 degrees Fahrenheit ^[1][2]. So does a compounded vial. Cold medication stings going in. Pull the pen or vial out 15 to 30 minutes before you inject and let it warm on the counter. Do not microwave it. Do not run it under hot water.
3. The supplies. Pen needle for a pen (Novo Nordisk recommends NovoFine or NovoTwist pen needles for Ozempic and Wegovy). Insulin syringe for a vial. An alcohol pad. A sharps container.

How to use an Ozempic pen

Ozempic ships in three pen versions: a 2 mg/3 mL pen used for the 0.25 mg and 0.5 mg doses, a 4 mg/3 mL pen used for the 1 mg dose, and an 8 mg/3 mL pen used for the 2 mg dose ^[1]. Each pen has a dial. You dial the prescribed dose, you do not measure volume.

Step by step

1. Wash your hands. Soap, water, twenty seconds.
2. Check the pen. Look at the medication through the window. It should be clear and colorless. If it looks cloudy or has particles, do not use that pen.
3. Attach a new pen needle. Wipe the rubber seal at the tip of the pen with alcohol. Twist the pen needle on straight until it is tight. Pull off the outer needle cap (save it for disposal) and the inner needle cap (throw it away).
4. Flow check (only on a new pen). Dial to the flow check symbol, hold the pen with the needle pointing up, and press the dose button until a drop of semaglutide appears at the needle tip. If no drop appears after up to six tries, change the needle and try again. After the first flow check on a new pen, you do not repeat this step every week.
5. Dial your dose. Turn the dose selector until the prescribed dose lines up with the dose pointer. If your pen will not dial to the dose, it does not have enough medication left for that dose.
6. Pick a site. Abdomen (anywhere except a two-inch circle around the navel), front of thigh, or upper outer arm.
7. Wipe the site with alcohol and let it dry. Wet alcohol on the needle tip is one of the most common reasons people say the shot burns.
8. Insert the needle straight in at 90 degrees to the skin. No pinch needed for most adults with a 4 mm pen needle, but pinching is fine if you are very lean.
9. Press and hold the dose button. Watch the dose counter return to 0. Keep the button pressed and keep the needle in the skin for a slow count to six. This makes sure the full dose enters the tissue and does not leak back out as you pull the needle out.
10. Remove the needle. Slide the outer needle cap over the needle on a flat surface (do not aim at your fingers), unscrew the needle, and drop it into the sharps container.
11. Recap the pen and put it back in the fridge or keep it at room temperature, depending on how long you have been using it. See the storage section below.

How to use a Wegovy pen

Wegovy is a single-use, fixed-dose pen. There is no dial. Each pen contains one weekly dose of 0.25, 0.5, 1, 1.7, or 2.4 mg ^[2]. You inject it, you throw it away. The needle is built in and hidden until you push the pen against your skin.

Step by step

1. Wash your hands. Pull a pen out of the fridge and let it warm for 15 minutes.
2. Confirm the dose printed on the pen label matches your prescription. Wegovy is titrated up over 16 weeks (0.25, 0.5, 1, 1.7, 2.4 mg) and using the wrong strength pen is the most common Wegovy error.
3. Inspect the window. The liquid should be clear and colorless. If it is cloudy or discolored, swap pens.
4. Pull off the pen cap. Do not put it back on. Once the cap is off, the pen is armed.
5. Choose a site. Abdomen, thigh, or upper outer arm. Wegovy is approved to be injected by you, a caregiver, or someone else at your upper arm if a helper does it.
6. Wipe the site with alcohol and let it dry.
7. Press the pen flat against the skin at 90 degrees. A yellow bar in the window starts moving. You will hear a first click as the injection begins.
8. Hold the pen against the skin for a full count of six seconds after the second click. The yellow bar must fill the window completely. Lifting the pen too early is the number one reason people report a wet drop on the skin or a "leaking" Wegovy injection.
9. Lift the pen straight off. A small drop of blood is normal. Press the site gently with gauze. Do not rub.
10. Dispose of the whole pen in a sharps container. Wegovy pens are not refillable.

How to inject compounded semaglutide from a vial

Compounded semaglutide ships in a multi-dose vial with a rubber stopper. You use an insulin syringe (U-100, 1 mL or 0.5 mL) with a fixed 29 to 31 gauge, 5/16 inch (8 mm) or 1/2 inch (12.7 mm) needle.

Step by step

1. Wash your hands. Pull the vial from the fridge 15 minutes before you inject.
2. Wipe the rubber stopper with an alcohol pad. Let it dry. Do not shake the vial. Gently swirl if you want to mix; semaglutide does not need vigorous mixing.
3. Uncap the syringe. Pull the plunger back to the unit mark for your prescribed dose. Some people prefer to inject this air into the vial first to equalize pressure; either approach works with a flexible rubber stopper.
4. Insert the needle through the stopper. Invert the vial so the liquid covers the needle tip. Pull the plunger to the exact unit mark your pharmacy calculated for your dose. If you see an air bubble, tap the syringe to bring it to the top and push it back into the vial, then re-draw to the mark.
5. Withdraw the needle from the vial. Recap if you are walking to another room; otherwise keep the needle pointed up and away from skin and fabric.
6. Choose a site. Abdomen (avoid a two-inch circle around the navel and any scar tissue), front of thigh, or upper outer arm.
7. Wipe the site with alcohol. Let it dry completely.
8. Pinch a fold of skin if you are lean, or stretch it flat if you have more subcutaneous fat. Insert the needle at 90 degrees in one quick motion. The standard insulin syringe needle (5/16 or 1/2 inch) is engineered to land in subcutaneous tissue at 90 degrees on almost any body type.
9. Push the plunger slow and steady. A two to three second push for a small volume (under 0.5 mL) reduces the burn most people describe with fast injections.
10. Hold for five seconds, then withdraw the needle at the same 90-degree angle.
11. Press the site gently with a clean tissue or gauze. Do not rub.
12. Drop the whole syringe (do not recap, do not detach the needle) into a sharps container ^[3].

Where to inject: sites and rotation

Three FDA-approved subcutaneous sites for semaglutide ^[1][2]:

• Abdomen. Anywhere outside a two-inch circle around the navel. Avoid scars, stretch marks, or any area that is bruised or red.
• Front or outer thigh. The middle third, between the hip and the knee. Avoid the inner thigh (more nerves, more blood vessels close to the surface).
• Upper outer arm. The fleshy area between the shoulder and the elbow. Most people need help reaching this site cleanly. If you are injecting yourself, the abdomen or thigh is easier.

Absorption from all three sites is clinically equivalent for semaglutide ^[2]. Pick whichever is most comfortable.

Site rotation

Rotate sites between weekly injections to reduce skin and fat tissue irritation. A simple rotation that works:

• Week 1: left abdomen
• Week 2: right abdomen
• Week 3: left thigh
• Week 4: right thigh
• Week 5: left arm (if you have help) or back to abdomen
• Week 6: right arm or back to abdomen

You do not have to use every site. Many people rotate left abdomen, right abdomen, left thigh, right thigh and never use the arm. The rule that matters is do not inject into the exact same square inch two weeks in a row.

Pinch or no pinch, and how deep to inject

Subcutaneous means into the layer of fat just under the skin, not into the muscle below it. Semaglutide pen needles are short (4 to 6 mm) and engineered so that pinching is optional for most adults. With a 4 mm pen needle, no pinch and a 90-degree insertion is the default approach ^[1][2].

For compounded vials with a 5/16 inch (8 mm) or 1/2 inch (12.7 mm) insulin syringe needle, pinch a small fold of skin if you are lean. If you have more abdominal fat, stretching the skin flat works fine. The needle still goes in at 90 degrees. A 45-degree angle is only needed for very thin arms or very thin children, and that is rarely the situation for adults on semaglutide.

Needle size for semaglutide

• Ozempic and Wegovy pens: NovoFine or NovoTwist pen needles, 32G x 4 mm typically. The pen is designed for these needles. Your pharmacy ships them with the pen.
• Compounded vials: U-100 insulin syringe, 29 to 31 gauge, 5/16 to 1/2 inch. The 5/16 inch (8 mm) is the most common and is sufficient for nearly every adult.

You can order more pen needles through your pharmacy if you run out before the pen does. Most insurance plans cover pen needles as a separate item.

What if I see blood, a bubble, or a leak

A small bead of blood at the injection site is normal and means a tiny capillary was nicked on the way in. Press with gauze for thirty seconds. The dose is fine. Semaglutide is absorbed from subcutaneous tissue over hours, not minutes, and a nicked capillary does not change the absorption curve in any meaningful way.

A small wet drop on the skin after a Wegovy injection usually means the pen was lifted off too early. Hold for the full six-second count after the second click and the leak goes away. A drop of semaglutide on the surface is a small fraction of the dose; do not redose. Just hold longer next week.

A visible bubble or small lump under the skin after an injection is medication that has not yet absorbed. It flattens out over a few hours. Do not massage it. If the lump is hard, hot, painful for more than 48 hours, or growing, call your prescriber.

What if I inject into a muscle by accident

Semaglutide injected intramuscularly absorbs faster than subcutaneous semaglutide. That can mean more nausea and more GI side effects for that week, but it is not an emergency. Drink fluids, eat blandly, and ride it out. The error happens most often when someone uses a needle longer than the standard pen needle on a very lean limb, or when the injection is done into the buttock (deeper tissue layers there). Stick to abdomen, thigh, and upper outer arm with the supplied needles and intramuscular injection is very rare.

Does the injection sting or burn

Cold medication, alcohol still wet on the skin, and a fast plunger push are the three biggest pain triggers. Fix all three:

• Take the pen or vial out of the fridge 15 to 30 minutes before injecting.
• Wipe the site with alcohol, then wait until it is fully dry.
• Push the plunger over two to three seconds, not in a quarter second.

Wegovy at higher doses (1.7 and 2.4 mg) stings more than Ozempic at lower doses for some people. Slow the push, warm the pen longer, and rotate sites diligently. A burning sensation that lasts seconds is normal. Burning that lasts an hour, or a red rash that spreads more than two inches from the site, is a local reaction. Cool compress, antihistamine if you tolerate one, and report it to your prescriber.

Storage

Do not freeze any semaglutide product. A frozen Ozempic or Wegovy pen is no longer safe to use, even if it thaws back to liquid. Keep pens away from direct light. Keep the pen cap on between uses.

Missed dose

If you remember within five days of the scheduled day, inject as soon as you remember. Then stay on your original weekly schedule.

If more than five days have passed, skip that dose. Inject your next dose on the regular day. This is the FDA-labeled rule for both Ozempic and Wegovy ^[1][2]. Do not double up. Doubling a missed weekly dose increases nausea and vomiting without a meaningful change in long-term efficacy.

You can change your weekly injection day if at least 48 hours have passed since your last dose. Inject on the new day, then continue weekly from that day forward.

Disposing of pens and syringes

Used pens, used insulin syringes, and used pen needles go into a sharps container. Not the kitchen trash. Not a plastic bottle on the counter (the CDC accepts heavy-walled household containers like an empty laundry detergent jug as a last resort, but a labeled sharps container is the standard) ^[3].

When the container is three-quarters full, follow your state's disposal rules. Most states accept sharps containers at pharmacies, hospitals, or community drop-off sites. Some allow sealed containers in the trash with a label. The federal site safeneedledisposal.org has a state-by-state lookup.

Common questions about injecting semaglutide

Where is the best place to inject semaglutide?

Abdomen, front of thigh, or upper outer arm. Absorption is the same from all three. The abdomen is the easiest for self-injection and is the most common choice.

Do I have to pinch my skin to inject Ozempic?

No. Ozempic pen needles are 4 mm and designed for a straight 90-degree insertion without pinching. Pinching is fine if you are very lean or more comfortable that way.

How deep does the needle go for semaglutide?

4 to 6 mm for brand pen needles, 8 to 12.7 mm for standard insulin syringes used with compounded vials. Both reach subcutaneous tissue at 90 degrees.

What size needle do I need for semaglutide?

NovoFine or NovoTwist 32G x 4 mm pen needles for Ozempic and Wegovy pens. A U-100 insulin syringe with a 29 to 31 gauge, 5/16 inch needle for compounded vials.

Can I inject Ozempic in my thigh?

Yes. The front of the thigh is one of the three FDA-approved sites alongside the abdomen and upper outer arm.

Is it better to inject Ozempic in the stomach or the thigh?

Neither is better for absorption. Most people pick whichever is more comfortable and easier to see. The abdomen wins on both counts for most users.

Does the semaglutide injection hurt?

Mild sting at most. Warm the medication for 15 minutes before injecting, let the alcohol fully dry, and push the plunger slowly. Those three steps cut the discomfort by most of what people report.

Why did my Wegovy shot hurt more than usual?

Higher Wegovy doses (1.7 and 2.4 mg) sting more for some people. Cold medication and a fast push make it worse. Warm the pen longer and slow the injection.

What if I accidentally injected semaglutide into a vein?

Subcutaneous semaglutide rarely reaches a vein with short pen needles. If blood draws back into the syringe before you push, stop, withdraw, press the site, and re-stick in a new spot two inches away with a fresh needle.

What happens if I inject semaglutide into a muscle?

It absorbs faster than subcutaneous, which can mean more nausea for that week. It is not an emergency. Stick to standard sites and pen needles to avoid it next time.

How long do I hold an Ozempic pen against my skin after injecting?

Six seconds after the dose counter reaches 0, with the needle still in the skin and the dose button pressed. That prevents leakage.

How long do I hold a Wegovy pen against my skin?

Six seconds after the second click, with the yellow bar fully filling the window.

What do I do with used pens and needles?

Drop them into a sharps container. When it is three-quarters full, take it to a pharmacy, hospital, or community drop-off site. Do not put loose needles in household trash.

How should I store Ozempic and Wegovy?

Refrigerate at 36 to 46 F until you start the pen. After first use, Ozempic is good at fridge or room temperature up to 86 F for 56 days. Wegovy is single use.

What do I do if I miss a semaglutide dose?

Within five days: inject when you remember and keep your weekly schedule. More than five days: skip and resume on the next regular day. Do not double the dose.

Can I reset my Ozempic pen?

No. If a dial is set wrong, dial back to your prescribed dose before injecting. If the pen is malfunctioning or will not dial, call your pharmacy. Do not try to disassemble the pen.

What this guide does not cover

This article is the mechanics of injection. Dosing schedules, titration timing, drug interactions, and side effect management have their own dedicated pages on this site. If you are new to semaglutide and have not started your first dose yet, talk to your prescriber about the right starting dose for your treatment goal before you use any of the steps above.