Once you dissolve our methyl B12 in saline, you’ll need to use syringes with needles so that you can inject it. You can choose syringes designed to deliver the medication either into muscle tissue or into fat tissue (subcutaneously). We prefer subcutaneous, because it is painless, effective, very easy to do by yourself, and carries no risk of nerve injury.
Every day, millions of people around the world inject insulin subcutaneously. This means that the needles designed for insulin purposes naturally work well for B12 shots.
So, what is the best needle for B12 injections?
B12 Injection Needle Size & Gauge
Needle size pertains to the length of the needle, which determines its penetration depth and is measured in millimeters (mm). Gauge, on the other hand, signifies the thickness or diameter of the needle, with a higher gauge number indicating a thinner needle. The following are our recommended vitamin B12 needle size and gauge:
B12 Shots Needle Size (Length)
For B12 injections done subcutaneously, we suggest using shorter 4-5mm needles, to minimize the risk of accidentally piercing muscle tissue:
Needles >or=8 mm, inserted perpendicularly, may frequently enter muscle in limbs of males and those with BMI <25 kg/m(2). With 90 degrees insertion, needles 4-5 mm enter the subcutaneous tissue with minimal risk of IM injection in virtually all adults.Skin and subcutaneous adipose layer thickness in adults with diabetes at sites used for insulin injections: implications for needle length recommendations
Shorter needles are also less painful, because they penetrate less tissue:
The needle lengths that were once recommended for SC injection (for adults, ≥8 mm; for children, ≥6 mm) are now known to be too long because they increase the risk of IM injections without evidence of improved glucose control. Shorter needles are much safer and are better tolerated and less painful.New Insulin Delivery Recommendations
The 4-mm needle was shown to be safe and efficacious in adult patients of all sizes; skin leakage was equivalent and pain scores were improved with the 4-mm needle. Similar studies have been performed in various other groups, including obese patients.
Traditional subcutaneous needle sizes extend up to 12.7mm, a length historically used for such injections. However, we now know that these longer needles are excessive. The research above indicates that 4mm needles are less painful, just as effective (even for obese patients), and carry no risk of penetrating muscle tissue (even in lean people).
In general, the shorter the needle, the lower the risk of injecting into muscle by mistake, especially in people with minimal subcutaneous fat. Also, when Becton Dickinson introduced their BD Ultra-Fine™ 6mm needle, they reported that 80% of patients preferred these shorter needles over the 8mm and 12.7mm alternatives.
So, if you can acquire 4mm or 5mm needles, we recommend using them. If not, 6mm or 8mm needles will also work. Just ensure that you pinch the skin if the injection site is too lean. This is why we advise using the area around the belly button.
Needle Gauge for B12 Injection (Diameter)
The gauge of a needle pertains to its diameter and plays a crucial role in both patient comfort and the rate at which B12 is delivered into your subcutaneous fat tissue.
For instance, a thicker 25G gauge may offer faster B12 delivery but could result in more discomfort. On the other hand, a 30G gauge represents thinner, less painful needles at the cost of slower delivery. When choosing a gauge, consider your skin thickness and the viscosity of the B12 solution; a thicker solution may need a slightly thicker needle.
From our experience, we’ve had positive experiences with higher gauges, like the 30-31G needles from Insumed and BD. These thinner needles cause minimal discomfort, even if they add a few extra seconds to the injection time, which we consider worthwhile. This choice is personal, however. For example, our reader Becky prefers 23G needles:
So, try a few different gauge levels to determine which one suits you best.
You Can Also Go Needle-Free
If you have a fear of needles, you can completely avoid them by using needle-free injectors such as the Comfort-in™. These devices propel liquid through the skin into the fat tissue using high-pressure, allowing you to inject B12 or any other liquid injectable without the need for a needle. No pain, no fear, and no accidental needle pricks.
The Comfort-in™ injector is one of the best syringes for B12 injections if you prefer needle-free shots. It’s affordable, designed for subcutaneous use, allows dose adjustment, and is available for direct purchase without the hassle of a prescription.
If you can’t tolerate even thin, modern needles such as those measuring 4-6mm / 30-31G, consider a needle-free injector like the Comfort-in™.
Based on the current research and our experience, which needles for vitamin B12 injection should you opt for? The best needle for B12 injection into fat tissue would be within the 4-5mm size range, combined with a gauge of 30G or higher.
The 4mm needle is long enough to traverse the skin and reach the subcutaneous tissue with minimal risk of intramuscular or intradermal penetration. It’s considered the safest choice for both adults and children, regardless of age, gender, ethnicity, or BMI. And the higher, thinner gauge guarantees as little pain as possible from a needle.
Here are some final tips from the New Insulin Delivery Recommendations paper:
- Ensure that the skin is clean and dry before injecting. Patients usually do not need to use a disinfectant on the skin, but if they do, they should allow it to dry completely before injecting.
- Use needles of shorter length (4 mm or the shortest available) and smaller diameter (highest gauge number), and the tip with the lowest penetration force to minimize pain. Use a sterile, new needle with each injection.
- Insert the needle through the skin in a smooth but not jabbing movement. Pain fibers are in the skin, and going through the skin too slowly or too forcefully may increase the pain.
If you can’t find 4-5mm needles, 6-8mm ones can also be suitable as long as you inject into an area with enough fat, such as around the belly button. Pinch the fat when you inject, to prevent accidental muscle penetration, and you should be alright.
Of course, feel free to experiment with various sizes and gauges to know for certain which needles for B12 shots you personally like best. And, if you want to eliminate the needle factor entirely, you can opt for a needleless injector instead.