A lancet is a small, sharp device used to prick the skin, typically the fingertip, to obtain a blood sample for glucose monitoring. While these devices are designed for precision and minimal discomfort, reusing lancets introduces several preventable health risks, often driven by cost or convenience. This article provides clear, evidence-based guidance on the safest and most effective way to use these monitoring tools.
The Standard Guideline for Lancet Changes
The definitive medical recommendation from manufacturers and health organizations is to use a new lancet for every single blood glucose test. Lancets are classified as single-use devices, meaning they are engineered for one puncture and should be discarded immediately afterward. This strict adherence to the “one-and-done” rule is the core principle of maintaining hygiene and ensuring safety during the testing process.
This guideline applies even when an individual tests several times a day or when using the same lancing device on themselves. Although the lancet remains housed within the lancing device, its tip is compromised and contaminated after the first use. Replacing the lancet for each test is the only way to guarantee a sterile and optimally sharp point for the next skin puncture.
Understanding the Risks of Lancet Reuse
Reusing a lancet introduces two primary risks: physical trauma caused by a dull needle and the biological danger of contamination. Both factors significantly compromise the safety and comfort of blood glucose monitoring.
Physical Degradation
A lancet tip suffers microscopic damage immediately upon piercing the skin, resulting in a dulling effect that is invisible to the naked eye. This physical degradation means that subsequent punctures require more force, leading to increased pain, bruising, and micro-tears in the skin tissue. Bench tests have demonstrated that the pierce force efficiency can drop by as much as 52% after just one reuse, making the second stick noticeably more traumatic.
Repeated trauma to the fingertips can cause the skin to become calloused and hardened over time, making it increasingly difficult to obtain an adequate blood sample. A dull lancet can also cause an inadequate puncture, forcing the user to squeeze the finger more aggressively. This action can introduce excess tissue fluid into the blood sample, potentially resulting in an inaccurate glucose reading and errors in medication dosing.
Biological Contamination
The moment a lancet pierces the skin, it becomes contaminated with surface bacteria, even if the skin was cleaned prior to the test. This biological contamination presents a direct pathway for pathogens to enter the bloodstream upon subsequent use. One study found that 34% of lancets cultured after a single reuse contained Staphylococcus aureus, a common bacterium that can cause significant skin and soft tissue infections.
While the risk of a major systemic infection is generally low for a healthy individual, it is entirely preventable by using a new, sterile lancet each time. The danger of cross-contamination is also severe if a lancet is accidentally shared, even within a family. Bloodborne pathogens like Hepatitis B, Hepatitis C, and HIV can be transmitted through microscopic traces of blood remaining on the needle.
Proper Handling and Disposal of Used Lancets
Because lancets are sharp, potentially contaminated medical waste, their safe handling and disposal are necessary after every test. Lancets are classified as “sharps” and must never be tossed directly into household trash or recycling containers. Improper disposal poses a serious injury and infection risk to sanitation workers, household members, and pets.
The preferred method for disposal is to place the used lancet immediately into an FDA-cleared sharps disposal container. These containers are specifically designed to be puncture-proof and feature a secure, tamper-resistant lid.
If an FDA-cleared container is not available, a heavy-duty, puncture-proof plastic container with a tight-fitting, screw-on lid can serve as a temporary alternative. A plastic laundry detergent bottle or a similar container with thick walls is often recommended for this purpose. The container should be clearly labeled as “Contains Sharps—Not for Recycling” and kept out of the reach of children. Once the container is about three-quarters full, the lid must be securely sealed with strong tape, and the container should be disposed of according to local regulations, which may involve supervised collection sites, hospital drop-offs, or mail-back programs.