Fildena 150 mg (sildenafil), you can generally tell it’s working if: You become sexually aroused and are able to get an erection more easily. The erection is firmer and easier to maintain during sexual activity. It does not cause an erection automatically—sexual stimulation is still needed. It usually starts working within about 30–60 minutes and can remain effective for several hours. Important  Fildena 150 mg  is higher than the commonly recommended maximum sildenafil dose of 100 mg in 24 hours. Don’t take another dose the same day or increase the dose because you don't notice an effect. If you have an erection lasting more than 4 hours, seek emergency medical care immediately. If you tell me when you took the 150 mg, whether you ate beforehand, and what effect you're experiencing, I can help you understand whether it’s likely working.