There is no known interaction between spirulina and aspirin that would render the aspirin ineffective or alter its chemical structure. Aspirin is typically absorbed in the stomach and small intestine, and there is no evidence to suggest that spirulina interferes with this process.
However, it's essential to keep in mind that everyone's body may react differently to medications and supplements. If you have any concerns about combining spirulina and aspirin or are taking other medications, it's best to consult with a healthcare professional or pharmacist to ensure there are no potential interactions or adverse effects specific to your situation. They can provide personalized advice based on your medical history and current medications.