There is a sticky here on Nigella Sativa. I put up a thread and Bull made it a sticky. Most of the ones I recommend also help with inflammation and other issues you can have with a somewhat significant cycle.
Always get to a doc if you have BP issues and discuss meds which you already know but I got the impression you were referring to alternatives and if using them and then stopping if there was a problem. If that is the case then yes, I can list 3 that should/will most likely keep your BP in check. They do not replace a doctor's advice or a doctor monitoring you but I am older than you, had higher BP for a while and brought it down and my RHR to around 50 with supplements. I hate cardio unless it is two items I enjoy doing - you will never see me on a stationary bike, stepper, etc.
Look at
@Funnyman as an example - he uses some supplements, is older, and has an excellent BP. I suspect his diet also has a part to play.
Only issue is cost of Carleson's fish oil - it is expensive but consider it one of the best and that brand recommendation came from Funnyman. We can say something is expensive but then again it doesn't matter how much cash you have if you don't have your health or even worse.
If this is what you meant - I can list the three I find to work well and are not expensive except for the fish oil. Some people use Costco or Walmart brand and are content with it too.
Just an opinion but don't wait for it to go up and treat it, if your going on a cycle take supplements along with the cycle - they help with inflammation, lipids, BP, etc. Hopefully, they prevent you from fighting to get it back down and stop it from ever getting high. If it does - listen to the wise people above and get a script from your doctor. You don't need to buy UGL meds - any doc will prescribe BP meds and with literature taken in with you and a preference for a specific drug, any non arrogant doc will give you telmisartan.