There are 4mm, 5mm and 8mm insulin needles on the market, and the two main factors for choice are thickness and length. The thickness of the needle is indicated by the letter G, and the larger the value in front of G, the thinner the needle.

For example, a 31G needle is thinner than a 30G needle, a 32G needle is thinner than a 31G needle, and a 33G needle is less painful than a 32G needle.

In general, the finer the diameter of the needle (i.e., the greater the G-value), the less pain and tissue bruising there will be for the patient. For example, the 34G needle is the thinnest of the needles currently on the market, and therefore causes the least pain and bruising.

The length of the needle is expressed in millimeters (mm), and in general, 4mm and 5mm needles are the most commonly used needles. Insulin must be properly injected into the subcutaneous tissue layer to ensure stable absorption of insulin, and choosing the correct length of the pillow is one of the keys to ensuring this.

Studies have shown that for both children and adults, normal weight and overweight patients, as long as the correct injection method is used, the 5mm needle can meet the needs of effective injection.

The combination of thickness and length constitutes a certain size of needle, such as 0.25*4mm, or 0.25*5mm, under the guidance of doctors and nurses, patients can choose the appropriate size according to their needs.

In order to meet the requirements of long-term, effective and accurate insulin injection, high-quality needles must be comprehensively considered and refined in terms of thickness, length, sharpness, smoothness, firmness and other aspects, so as to minimize pain and bruising caused by long-term injection, so as to improve treatment compliance and long-term blood sugar control.