Aspirin and all other non-steroidal anti-inflammatory drugs (NSAID’s) affect blood clotting by inhibiting the ability of platelets to gather and clump. A platelet is one of the 2 part clotting mechanism in the body. The initial response to an injury (such as a cut on the skin or a trauma to a blood vessel) is the attraction of platelets to the site. They begin to clump and release substances that attract more platelets (like ants to a picnic). As this occurs, these substances induce a complex multi-step process of enzymes and proteins that ultimately cause the formation of a substance known as fibrin. (BTW, genetic problems in this enzyme cascade can cause diseases such as hemophilia). The fibrin forms a matrix inside the platelet clump, making the clot firm - vous-a-la the bleeding stops. In a blood vessel, one of the substances released by platelets cause the vessel to constrict making it easier for the clot to form and harden, leading to a thrombosed vessel, either on the surface of your skin to stop bleeding or possibly in an unlucky veins on the surface of the penis.
These two mechanisms can be effected by different classes of medications. Lets dispense with inhibiting fibrin first. The drugs heparin (given by vein in hospitals or under the skin by users) and Coumadin (warfarin - the active ingredient of most rat poisons) and the new drug Eliquis (and there are others), all affect the multi-step cascade of proteins leading to fibrin formation. They affect it at different steps and by different means. Doctors give these meds for severe clotting problems, such as thrombosis of the deep veins of the legs which could cause a clot to travel to the lung (pulmonary embolism) - not a good thing. They also give them frequently now for the most frequent heart rhythm disorder - atrial fibrillation. This can prevent the formation of clot in the left atrium which can lead to stroke. Great drugs — VERY DANGEROUS. They are not given willy-nilly. and must be monitored. You don’t want to be on one. They have no known affect on erection and I don’t want to find out personally, thank you very much…
Aspirin on the other hand is a drug that has been around “since antiquity.” It is the product of the bark of willow trees. It was made into teas and other things and it was found to decrease irritation and pain. It was first purified in the late 1890’s by a small drug and dye company named Bayer and they called it aspirin; the rest is history…It was the non-narcotic pain relieving drug of choice and anti-fever medication until the development of Tylenol (acetaminophen) and paracetamol (in Europe) and after 1970’s when it was found to cause Reyes syndrome in kids. It has lots of side effects (bleeding, gastric ulcers, hemorrhagic strokes, profound allergies, just to name a few). I dare say that if it came before the FDA today for approval, they probably would turn it down. That being said, when used properly it is a great drug.
Platelets live for about 28 days. They are made all the time in the bone marrow. Aspirin inhibits platelets permanently - even in small doses. They become “impotent” so to speak. This makes aspirin so important as a prevention of heart attacks. Never fear, even without active platelets, your blood will clot, just not as fast…The other NSAID’s (ibuprofen, naproxen sodium and a host of other prescription NSAID’s) also affect platelets, but only temporarily; generally 24 to 48 hours.
While there are questions as to whether ibuprofen and naproxen sodium (and the others) cause ED, there is no evidence for aspirin affecting erection (bad or good). I personally take 2 adult strength enteric-coated aspirins twice a day for medical reasons and I don’t have ED, thank you very much…
As for the use of the term “blood-thinners”…This is a misnomer. First of all, generally speaking, aspirin is not called a blood thinner. But in reality, as posted above, heparin, Coumadin, Eliquis, etc. do not do anything to the thickness of the blood - they simply stop clotting by inhibiting the complex protein chain leading to clotting.