What Happens If Semaglutide Is Not Injected Deep Enough?

October 9, 2025 •

4 min read

According to a review of clinical trials, injection site reactions were reported by less than 1% of patients using Ozempic, but improper technique is a known cause of discomfort. So, what happens if semaglutide is not injected deep enough? This common mistake can lead to a range of issues, from skin irritation to diminished therapeutic effects.

Quick Summary

Injecting semaglutide too shallowly can cause erratic and diminished drug absorption, reducing its effectiveness. Common consequences include injection site pain, burning, swelling, or the formation of a temporary lump under the skin.

Key Points

Reduced Effectiveness: Injecting semaglutide too shallowly can cause inconsistent and diminished absorption, reducing the medication's intended therapeutic effects for blood sugar control and weight loss.
Increased Pain and Discomfort: A shallow injection into the skin's dermis layer, which is rich in nerve endings, can be more painful and cause stinging or burning sensations.
Higher Risk of Skin Reactions: Injecting improperly can lead to common injection site issues like redness, swelling, bruising, and the formation of a temporary lump or "bubble" under the skin.
Proper Technique is Essential: To ensure effective absorption and minimize side effects, semaglutide must be injected into the fatty subcutaneous tissue using correct form, including a 90-degree angle and slow, steady delivery.
Site Rotation Prevents Damage: Consistently using the same injection spot can cause skin irritation or fatty lumps, so rotating between recommended sites (abdomen, thigh, upper arm) is crucial.
Monitor for Serious Signs: While mild reactions are common, persistent pain, spreading redness, pus, or fever are signs of infection or other serious issues that require immediate medical attention.

Understanding the Semaglutide Injection

Semaglutide, available under brand names like Ozempic and Wegovy, is a GLP-1 receptor agonist prescribed for type 2 diabetes management and weight loss. Its unique chemical structure allows it to have a long half-life, requiring only once-weekly subcutaneous injections. A subcutaneous injection involves depositing the medication into the fatty tissue just beneath the skin, allowing for slow, consistent absorption into the bloodstream. This method ensures steady drug levels over the course of a week, which is crucial for its effectiveness.

The Consequences of a Shallow Injection

A shallow injection, also known as an intradermal injection, places the medication into the dermis—the layer of skin above the fatty subcutaneous tissue. The dermis has a different blood supply and tissue density than the subcutaneous layer, which disrupts the medication's intended absorption profile. Injecting too shallowly can result in a range of side effects and reduced efficacy:

Inconsistent or Diminished Absorption: Clinical trials and guidelines for semaglutide are based on subcutaneous administration. When the drug is not delivered to the correct fatty layer, its absorption can be erratic or incomplete. This means the body receives a lower, less predictable dose than intended, which can undermine the medication's ability to regulate blood sugar or reduce appetite effectively.
Increased Pain and Discomfort: The dermis is rich in nerve endings, making a shallow injection more painful than a proper subcutaneous one. Patients often report a burning or stinging sensation that can last for a while after injection.
Injection Site Reactions: The body may react to the medication being deposited in the wrong layer, leading to localized skin reactions. This can include:
- Redness and swelling
- Bruising, which occurs more easily in the dermis layer
- Formation of a temporary bubble or lump under the skin where the medication has pooled
Risk of Leakage: Because the dermis has less space to hold the injected fluid compared to the fatty subcutaneous layer, there is a higher chance of the medication leaking out after the needle is withdrawn, further reducing the dose.

Comparison of Injection Depths and Outcomes


Aspect	Shallow (Intradermal) Injection	Correct (Subcutaneous) Injection	Deep (Intramuscular) Injection
Injection Target	Dermis layer, just under the epidermis	Fatty layer beneath the skin	Muscle tissue
Absorption Rate	Erratic, slow absorption, inconsistent	Slow, steady, and predictable	Faster absorption, inconsistent with semaglutide
Therapeutic Effect	Diminished, potentially ineffective	Optimal, as intended by manufacturer	Potentially altered or inconsistent
Pain Level	Higher due to high nerve concentration	Minimal, typically a slight pinch	Higher, with potential for more discomfort
Common Side Effects	Redness, swelling, bruising, burning, small lumps	Minor tenderness or redness may occur	More pain, tissue damage, or inflammation

Perfecting Your Semaglutide Injection Technique

To avoid the pitfalls of a shallow injection, following the correct procedure is essential. Proper technique ensures the medication is absorbed correctly and minimizes discomfort.

Steps for a successful subcutaneous injection:

Prepare: Wash your hands thoroughly. If the pen is refrigerated, let it warm up to room temperature for 15-30 minutes to reduce stinging. Check the liquid in the pen to ensure it is clear and colorless.
Choose a Site: Select an injection site on the abdomen (at least two inches from the navel), thigh, or back of the upper arm. Rotate sites with each weekly injection to prevent skin irritation or tissue damage, like lipohypertrophy.
Clean the Area: Wipe the chosen site with an alcohol swab and let it air-dry completely. Injecting through wet alcohol residue can cause a burning sensation.
Inject: Pinch a fold of skin and fatty tissue between your thumb and forefinger. Insert the needle straight into the pinched skin at a 90-degree angle (or 45 degrees if you have very little body fat). Inject the medication slowly and hold the pen in place for six seconds after pressing the button to ensure the full dose is delivered.
Withdraw and Dispose: Remove the needle straight out and immediately dispose of it in a sharps container.

When to Contact a Healthcare Provider

While most mild injection site reactions resolve on their own, certain symptoms warrant professional medical advice. You should contact your healthcare provider if you experience:

Severe or worsening pain at the injection site that persists for more than a day
Signs of infection, such as increasing redness, warmth, pus, or a fever
A hard lump under the skin that appears to be growing
A widespread rash, which could indicate a more serious allergic reaction
Blistering or skin ulcers

Conclusion

Administering semaglutide correctly is fundamental to its safety and effectiveness. An injection that is not deep enough can hinder the medication's absorption, leading to inconsistent treatment outcomes and increased injection site discomfort. By understanding the proper subcutaneous technique—including choosing appropriate sites, rotating locations, and following the manufacturer's instructions—patients can maximize the benefits of their therapy while minimizing adverse effects. Adherence to proper injection protocols is a key part of the treatment plan for managing type 2 diabetes and achieving weight loss goals.

For additional details on proper medication administration, including instructions for semaglutide, consult official resources like MedlinePlus or your healthcare provider.

Frequently Asked Questions

A shallow injection might cause more pain, a burning or stinging sensation, and a visible bubble or lump under the skin that may take some time to dissipate. If the medication seems less effective over time, it could also be a sign of improper absorption due to shallow injection.

If you inject too shallowly, the medication's absorption will likely be diminished and inconsistent. This can result in reduced effectiveness for managing blood sugar or weight loss. While a single improper injection is not an emergency, repeated shallow injections can compromise your treatment outcomes.

A small, temporary lump or bubble can appear after a shallow injection where the medication has pooled, but this is usually harmless and should go away. You can apply a cool compress to the area for comfort. If the lump becomes hard, painful, or is accompanied by signs of infection like warmth or pus, contact your healthcare provider.

While it can cause discomfort and reduced effectiveness, a shallow injection of semaglutide is generally not dangerous. The primary risk is a compromised therapeutic effect. However, if you experience signs of a severe allergic reaction (like widespread rash or breathing difficulties) or a spreading infection, seek immediate medical attention.

The correct depth is into the fatty subcutaneous tissue, which is just below the skin. For most people, a 90-degree angle is recommended, while for those with less body fat, a 45-degree angle may be necessary. Pinching a skin fold before injecting helps ensure you hit the fatty layer.

To prevent shallow injections, always use a fresh needle, pinch a fold of skin and fatty tissue, insert the needle at the appropriate angle (usually 90 degrees), and ensure the alcohol swab is completely dry before injecting. Rotating injection sites also helps maintain healthy tissue for proper absorption.

The recommended sites for subcutaneous semaglutide injections are the abdomen (at least two inches from the navel), the thigh (front or side), and the back of the upper arm. You must rotate between these sites with each dose.

Yes, injecting cold semaglutide can cause a burning or stinging sensation and increase discomfort. It is recommended to let a refrigerated pen warm up to room temperature for 15-30 minutes before injecting.