Viagra ki wajah sey agar tanau (erection) 4 hours sey zyada rahey to foran doctor ka pass jaein warna insan mustaqil namardi ka shikar ho sakta hai. Viagra khali pait li jati hai. Ek bar mubashrat (Intercourse) kay baad agar 24 hours kay baad phir mubashrat (Intercourse) ki koshish kari jaey to phir iss ka asar shuru hojata hai. Baaz mardon kay liye viagra ek do dafa istemaal karney sey effective nahi hoti. Iss soorat mein yeh 3rd aur 4th time effective sabit hoti hai. 

    Viagra aur iss tarhan ki adviyat (medicine) har insan kay liye nahi hai. Aisey log jinko recently heart attack hua ho woh iss ko istemaal na karein. Iss kay elawa hypertensive aur hypotensive log bhi isko use na karein, heart aur kidney ki beemari kay patient bhi iss ko use na karein. Issi tarhan stomach ulcer aur khoon ki beemariyun ki soorat mein viagra ko use na kya jaey. Baaz adviyat (medicine) kay sath bhi iss ka use nuqsan deh hai maslan high blood pressure ki medicines, Nitrite wali medicines (Isosorbide, Angised etc) issi tarhan viagra ko angina ki adviyat (medicine) kay sath bhi use na kya jaey.  

    Yeh tablets 100mg ki packing mein aati hain. Iss ki safe dose 50 mg hai. Aksar logon kay liye 25mg effective hai. Jin logon ko lever ya kidney ka masla hai yeh jo aids ki medicines ley rahey hain woh 25mg sey zyada na lein. Issi tarhan 60 years ki age kay baad iss ki safe dose 25mg hai. Aisi adviyat (medicine) week mein ek bar leni chahiyien. Week mein 2 dafa sey zyada to har giz na li jaein. Darmiyani waqfa kam sey kam 2 days ka ho.