The price of generic and 100mg Viagra differs based on the retailer and location. PharmacyChecker.com lists the lowest price as $0.30 per tablet for 88 tablets. SingleCare.com provides a coupon reducing the price of 30 tablets to $7.19. Other retailers like Roman and Hims offer sildenafil starting at $2 per dose. Subscription services start at around $20 per month. Prices may vary, so it's advisable to check with the specific retailer for accurate pricing.

Pfizer, the creator of Viagra, received FDA approval for the drug in 1998. It's used for treating erectile dysfunction and contains the active ingredient sildenafil. Pfizer holds two patents for sildenafil, one for Revatio and another for Viagra. In 2013, they allowed Teva Pharmaceuticals to market a generic version. Pfizer also released their own generic version in 2017. Despite its success, with $1.6 billion in sales in 2016, Viagra's global share has declined due to competitors like Cialis and Levitra, and other generic sildenafil versions.

Sildenafil, the active ingredient in Viagra, is used for treating erectile dysfunction. Since Pfizer's patent expired in 2013, numerous manufacturers globally have produced generic sildenafil under various brand names. All brands contain the same active ingredient, sildenafil citrate, but may have different inactive ingredients. Only Pfizer can label their sildenafil as 'Viagra'. If you prefer a specific brand, customer service teams might assist.

Levitra has a shelf life of 24 months, approved by the FDA. It is not advisable to use Levitra after its expiration date as the composition and potency may change. It is recommended to dispose of expired medication as per FDA guidelines.

Buspar, also known as buspirone hydrochloride, has been removed from the market, but its generic counterpart, buspirone, is still accessible. The withdrawal was not related to safety or efficacy concerns. Buspirone can help with anxiety symptoms without causing withdrawal issues.