A few decades ago, psilocybin and psilocin were banned in the USA through the Controlled Substances Act in the year 1970. Although the legislation is clear about fully developed magic mushrooms, the legality of buying mushroom spore syringes containing magic mushroom spores can vary depending on your jurisdiction.
In many countries, selling and possessing magic mushrooms and spores are illegal. However, in some places, the spores themselves may be legal to own or sell, as they do not contain the active compounds (psilocybin and psilocin) responsible for the psychoactive effects of magic mushrooms. Therefore, you can purchase spore syringes for research, educational purposes.
To ensure you have accurate information about the legality of buying mushroom spore syringes, a good idea would be to consult the specific laws in your country, state, or region. And, of course, complying with local laws and regulation is always the best choice you can make.
At any rate, we must also add here that most shops that offer mushroom spore syringes that contain psilocybe spores require that their customers to be at least 18 years old. AND they specifically require those who are interested in purchasing such products to use them only for microscopy and scientific research.