I would recommend using a weather app/service which also monitors the pollen intensity and avoid high intensity days. Im using Breezy Weather from the F-droid app store.

Also nasal spray/eyedrops before or during the ride helps me a lot, just avoid rubbing your eyes with bare hands. I am using a big single-lense cycling glass to protect my eyes, also good against the wind.

I usually avoid taking tablets as they make me feel drowsy (even the non-drowsy ones)

I wear a single layer cloth mask for running as that’s where I suffer the worst. Makes it really hot and heavy but still infinitely better than wheezing the whole time.

I don’t really need it for cycling but it’s tempting for combating exhaust fumes too.