Internet‐Ordered Viagra (Sildenafil Citrate) Is Rarely Genuine



      Counterfeit medication is a growing problem. This study assessed the requirement for prescription, cost, origin, and content of medications sold via the Internet and purporting to be the phosphodiesterase type 5 inhibitor Viagra (sildenafil citrate).


      Pfizer monitored top search results for the query “buy Viagra” on the two leading Internet search engines in March 2011. Orders were placed from 22 unique Web sites claiming to sell Viagra manufactured by Pfizer. Tablets received were assessed for chemical composition.


      No Web site examined required a prescription for purchase or a health screening survey; 90% offered illegal “generic Viagra.” Cost per tablet ranged from $3.28–$33.00. Shipment origins of purchases were Hong Kong (N = 11), the United States (N = 6), and the United Kingdom (N = 2) as well as Canada, China, and India (N = 1 each). Notably, the four Internet pharmacies claiming to be Canadian did not ship medication from a Canadian address. Of 22 sample tablets examined, 17 (77%) were counterfeit, 4 (18%) were authentic, and 1 (5%) was an illegal generic. Counterfeit tablets were analyzed for sildenafil citrate, the active pharmaceutical ingredient (API) of Viagra, and contents varied between 30% and 50% of the label claim. Counterfeits lacked product information leaflets, including appropriate safety warnings, and genuine Viagra formulations.


      Internet sites claiming to sell authentic Viagra shipped counterfeit medication 77% of the time; counterfeits usually came from non‐U.S. addresses and had 30% to 50% of the labeled API claim. Caution is warranted when purchasing Viagra via the Internet. Campbell N, Clark JP, Stecher VJ, and Goldstein I. Internet‐ordered Viagra (sildenafil citrate) is rarely genuine. J Sex Med 2012;9:2943–2951.


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      1. Combating counterfeit drugs [editorial].
        Lancet. 2008; 371: 1551
      2. Pitts P. Counterfeit drug sales to reach $75 billion by 2010, report says. The Heartland Institute. November 1, 2005. Available at: (accessed August 16, 2012).

        • Shepherd M.
        Beef up international cooperation on counterfeits.
        Nat Med. 2010; 16: 366
      3. Intellectual Property Rights. Fiscal Year 2010 Seizure Statistics—Final Report. In: U.S. Customs and Border Protection and U.S. Immigration and Customs Enforcement, ed; 2011.

      4. FY 2005 Top IPR Commodities Seized. In: U.S. Customs and Border Protection and U.S. Immigration and Customs Enforcement, ed. Los Angeles, CA, USA; 2005. Available at:‐of‐Homeland‐Security‐US‐Customs‐and‐Border‐Protection (accessed August 16, 2012).

      5. Medicines and Healthcare Products Regulatory Agency. Counterfeit medicines and devices. Available at: (accessed August 16, 2012).

        • Hellstrom W.J.
        The growing concerns regarding counterfeit medications.
        J Sex Med. 2011; 8: 1-3
        • Jack A.
        Counterfeit medicines. Bitter pills.
        BMJ. 2007; 335: 1120-1121
      6. Dorsey PJ, Hellstrom WJ. The illicit sale of medications for the treatment of erectile dysfunction. Medscape Urology 2007. Available at: (accessed August 16, 2012).

      7. Cracking counterfeit.
        Pfizer Inc, 2008
      8. Internet Drug Outlet Identification Program—Progress Report for State and Federal Regulators: July 2011. Mount Prospect, IL: National Association of Boards of Pharmacy; 2011. Available at: (accessed August 2012).

      9. The National Center of Addiction and Substance Abuse at Columbia University. “You've Got Drugs!” V: Prescription Drug Pushers on the Internet. New York: Colombia University; 2008.

        • Raine C.
        • Webb D.J.
        • Maxwell S.R.
        The availability of prescription‐only analgesics purchased from the internet in the UK.
        Br J Clin Pharmacol. 2009; 67: 250-254
      10. European Alliance for Access to Safe Medicines. The counterfeiting superhighway. Medicom Group Ltd. Available at: (accessed August 16, 2012).

        • Forman R.F.
        • Woody G.E.
        • McLellan T.
        • Lynch K.G.
        The availability of web sites offering to sell opioid medications without prescriptions.
        Am J Psychiatry. 2006; 163: 1233-1238
      11. World Health Organization International Medical Products Anti‐Counterfeiting Taskforce. Counterfeit drugs kill! 2008. Available at: (accessed August 16, 2012).

      12. European Committee on Crime Problems, Committee of Experts on the Operation of European Conventions in the Penal Field. Opinion on Parliamentary Assembly Recommendation 1673 (2004): Counterfeiting: Problems and solutions. Available at: (accessed August 16, 2012).

        • Jackson G.
        • Patel S.
        • Khan S.
        Assessing the problem of counterfeit medications in the United Kingdom.
        Int J Clin Pract. 2012; 66: 241-250
      13. The Partnership at 36 million Americans have bought medications online without a doctor's prescription. Research about dangerous practice—and the 11 internet commerce companies partnering together to protect patients—announced as part of White House Forum: Alliance for Safe Online Pharmacies; 2010. Available at:‐releases/36‐million‐americans‐have‐bought‐medications‐online‐without‐a‐doctors‐prescription‐111868434.html (accessed August 16, 2012).

      14. Hirschler B. Europeans spend billions on fake medicines: Survey: Reuters. 2010.

      15. 77 million Europeans fuelling counterfeits market. 2010. Available at:‐million‐europeans‐fuelling‐counterfeits‐market (accessed August 16, 2012).

      16. Aegate. Cost and convenience; reasons why consumers ignore dangers of buying fake drugs online. 2010.

        • Aldridge J.
        • Measham F.
        Sildenafil (Viagra) is used as a recreational drug in England.
        BMJ. 1999; 318: 669
        • Bechara A.
        • Casabe A.
        • De Bonis W.
        • Helien A.
        • Bertolino M.V.
        Recreational use of phosphodiesterase type 5 inhibitors by healthy young men.
        J Sex Med. 2010; 7: 3736-3742
        • Lowe G.
        • Costabile R.
        Phosphodiesterase type 5 inhibitor abuse: A critical review.
        Curr Drug Abuse Rev. 2011; 4: 87-94
      17. Fake drugs trade on the rise in the EU. 2009. Available at:‐news/Fake‐drugs‐trade‐on‐the‐rise‐in‐the‐EU‐_58769.html (accessed August 16, 2012).

        • Jackson G.
        • Arver S.
        • Banks I.
        • Stecher V.J.
        Counterfeit phosphodiesterase type 5 inhibitors pose significant safety risks.
        Int J Clin Pract. 2010; 64: 497-504
        • Eysenbach G.
        Online prescribing of sildenafil (Viagra) on the World Wide Web.
        J Med Internet Res. 1999; 1: e10
        • Kao S.L.
        • Chan C.L.
        • Tan B.
        • Lim C.C.
        • Dalan R.
        • Gardner D.
        • Pratt E.
        • Lee M.
        • Lee K.O.
        An unusual outbreak of hypoglycemia.
        N Engl J Med. 2009; 360: 734-736
        • Akunyili D.N.
        • Nnani I.P.C.
        Risk of medicines: Counterfeit drugs.
        Int J Risk Saf Med. 2004; 16: 181-190
        • Catizone C.A.
        Counterfeit drugs and states' efforts to combat the problem.
        J Pharm Pract. 2006; 19: 165-170
        • Solomon S.
        BC woman killed by fake drugs bought online: “Metal toxicity” from counterfeit pills reinforces danger of internet meds.
        Natl Rev Med. 2007; 4
        • Vanderdonck F.
        Counterfeit medicines: A threat to public health and safety.
        Louv Med. 2007; 126: S138-S142
        • Symonds T.
        • Dean J.
        • Coyne K.S.
        • Margolis M.K.
        • Hackett G.
        • Edwards D.
        • Marfatia A.
        • Schnetzler G.
        The ability of men to assess their suitability to take a phosphodiesterase type 5 inhibitor: An assessment of the comprehension of patient information materials.
        J Sex Med. 2010; 7: 2217-2225
        • Gallagher C.T.
        • Chapman L.E.
        Classification, location and legitimacy of web‐based suppliers of Viagra to the UK.
        Int J Pharm Pract. 2010; 18: 341-345
        • Armstrong K.
        • Schwartz J.S.
        • Asch D.A.
        Direct sale of sildenafil (Viagra) to consumers over the Internet [see comments].
        N Engl J Med. 1999; 341: 1389-1392
        • Bloom B.S.
        • Iannacone R.C.
        Internet availability of prescription pharmaceuticals to the public.
        Ann Intern Med. 1999; 131: 830-833
      18. US Food and Drug Administration. FDA operation reveals many drugs promoted as “Canadian” products really originate from other countries. 2005. Available at: (accessed August 16, 2012).

        • Deisingh A.K.
        Pharmaceutical counterfeiting.
        Analyst. 2005; 130: 271-279
      19. Blok‐Tip L, Vogelpoel H, Vredenbregt MJ, Barends DM, de Kaste D. Counterfeits and imitations of Viagra® and Cialis® tablets: Trends and risks to public. A survey of the analyses carried out at the Dutch National Institute for Public Health and the Environment in the time period 2000–2004. 2005. Available at: (accessed August 16, 2012).

        • Newton P.N.
        • Fernandez F.M.
        • Plancon A.
        • Mildenhall D.C.
        • Green M.D.
        • Ziyong L.
        • Christophel E.M.
        • Phanouvong S.
        • Howells S.
        • McIntosh E.
        • Laurin P.
        • Blum N.
        • Hampton C.Y.
        • Faure K.
        • Nyadong L.
        • Soong C.W.
        • Santoso B.
        • Zhiguang W.
        • Newton J.
        • Palmer K.
        A collaborative epidemiological investigation into the criminal fake artesunate trade in South East Asia.
        Plos Med. 2008; 5: e32
      20. Venhuis BJ, Barends DM, Zwaagstra ME, de Kaste D. Recent developments in counterfeits and imitations of Viagra, Cialis and Levitra: A 2005–2006 update. 2007. Available at: (accessed August 16, 2012).