Cotton Filters for Injection 101

A variety of adulterants in the drug supply contribute to the debris seen in your cooker when drugs are prepared for shooting up. This debris needs to be filtered out to avoid clogged syringes and more importantly to avoid it ending up in your veins. Debris in your veins can cause trauma, infections, and abscesses. Cotton pellets are effective filters that are commonly used to remove debris before shooting up.
Once your drugs are mixed with water or saline, a cotton pellet is placed into the cooker. The drugs are then drawn up from the cooker into the syringe through the cotton pellet. The cotton pellet will catch the debris to prevent it from entering the barrel of the syringe and ultimately from entering your body.


Cotton filters should be single use and never shared because they are a breeding ground for bacteria and can spread bloodborne pathogens, including Hepatitis C. Reusing a cotton pellet can lead to cotton fever or worse, endocarditis.
Cotton fever occurs when bacteria from a reused cotton pellet enters the bloodstream. Symptoms occur within 15 to 30 minutes and include fever, headache, nausea, chills, and muscle and joint pain. Though cotton fever is not life threatening, you may experience unrelenting discomfort. There is no cure or treatment for cotton fever though symptoms can be treated with fever reducers such as aspirin– over time, symptoms will subside on their own. Cotton fever can last anywhere from 6-24 hours.
Endocarditis occurs when the inner lining of the heart becomes inflamed due to an infection caused by external bacteria entering the bloodstream. Bacteria clumps will collect in the heart which can break off and travel to other parts of your body. People who inject drugs are six times more likely to develop endocarditis. These odds are lowered when you use sterile syringes, do not reuse cotton filters, do not reuse cookers, and properly clean injection sites before puncturing the skin.
Endocarditis is life threatening and individuals usually don’t know they have it right away. The longer endocarditis is left untreated, the more life threatening it will become. Symptoms of endocarditis include fatigue, aching joints, swollen limbs, and blood in urine. If you suspect you may have endocarditis, you should seek immediate medical attention. This cannot be treated without antibiotics or surgery depending on how far along the infection is. For more information on endocarditis please see our “Endocarditis” resource at nextdistro.org/inhouse-resources
When used properly, cotton filters are an important part of safer injection. If you want to get the most use out of your cotton filter, eat it. Eating your cotton filter after you’ve finished using it for your shot is the safest way to feel the effects of the drugs left in the filter without compromising your health.