It changes depending on the dose. Viagra is the most recognizable and well-known ED tablet. What do I need to know when buying Viagra online? Some men are okay with these side effects, and find signs like facial flushing reassuring because it helps them to know the drug is working. Cialis tadalafil : This ED medication works with the same principle as Viagra, but lasts up to 36 hours. Generic vs. Answer: Not always.Best Low Cost: GoodRx Fastest Delivery: Blink Health: Sesame Sign Up Now Key Specs Cost: Consultation prices vary based on the prescriber; $5 generic prescriptions Medical Consultation Required: Yes Medications Prescribed: Viagra, Cialis, sildenafil, tadalafil Generic offered: Yes Why We Chose It. Viagra is available in mg, mg, and mg doses and can be purchased in day and day supplies. Shipping is free, and your new medication can be sent discreetly to your home. Buy Viagra Online. Bye ED. For ED, Viagra is the first port of call. It’s been used by millions of men for over 20 years, and works by boosting circulation to the penis. We’re here to help you find the ED treatment you need. Order Viagra online and get your first package in 3 .