title: Adulteration of purported herbal and natural sexual performance enhancement dietary supplements with synthetic phosphodiesterase type 5 inhibitors.
abstract: BACKGROUND
  Many products labeled "herbal" or "all natural" (herbal/natural) that claim to enhance sexual performance and imply use for the treatment of erectile dysfunction (ED) are marketed as over-the-counter (OTC) dietary supplements. However, adulteration with undeclared phosphodiesterase type 5 (PDE5) inhibitors appears widespread.
  
  
  OBJECTIVE
  To assess the availability, cost, origin, categorical content, and adulteration with PDE5 inhibitors of purported herbal/natural OTC dietary supplements claiming to naturally enhance sexual performance.
  
  
  METHODS
  Pfizer Global Security coordinated sample collection (all from convenience stores and filling stations in two U.S. metropolitan areas except for seven from U.S. Customs seizures) and liquid chromatography/mass spectrometry examination.
  
  
  METHODS
  Adulteration with synthetic PDE5 inhibitors.
  
  
  RESULTS
  Ninety-one samples labeled as 58 distinct products and priced from $2.99 to $17.99 were evaluated. Origin/manufacture was claimed as United States (n = 62), apparently Asian (n = 15), and not clearly identified (n = 14). Although no sample claimed to include synthetic substances, 74 (81%) contained PDE5-inhibitor pharmaceutical ingredients, including tadalafil and/or sildenafil (n = 40, of which 18 contained >110% of the highest approved drug product strength) or PDE5-inhibitor analogs (n = 34). Pronounced heterogeneity of contents between samples within individual products indicated minimal quality control during manufacture. Labeling was inadequate (e.g., lacking lot number and/or expiry date) for 17 products (23 samples) and inconsistent between samples within a given product (e.g., in manufacturer, lot number, and/or expiry date) for seven of 17 products having multiple samples. Only 14 samples warned against concomitant nitrate use.
  
  
  CONCLUSIONS
  Ethical pharmaceutical companies are concerned for an unsuspecting public when their products are counterfeited, mislabeled, and illegally offered for sale in an unsafe manner. Because of the dangers of adulteration with synthetic PDE5 inhibitors, absent safety warnings, and lack of quality or consistent manufacture, men with ED unknowingly risk their health by using OTC herbal/natural products that claim to enhance sexual performance.
authors: Pfizer Inc., New York, NY 10017, USA. Neil.Campbell2@pfizer.com
authors: Neil
authors: N
authors: Campbell
authors: John P
authors: JP
authors: Clark
authors: Vera J
authors: VJ
authors: Stecher
authors: John W
authors: JW
authors: Thomas
authors: Amy C
authors: AC
authors: Callanan
authors: Brian F
authors: BF
authors: Donnelly
authors: Irwin
authors: I
authors: Goldstein
authors: Jed C
authors: JC
authors: Kaminetsky
mesh_terms: D002243:Carbolines / Q000032:analysis / Q000627:therapeutic use; D002853:Chromatography, Liquid; D019587:Dietary Supplements / Q000032:analysis*; D004348:Drug Labeling; D007172:Erectile Dysfunction / Q000188:drug therapy*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D004366:Nonprescription Drugs / Q000737:chemistry* / Q000627:therapeutic use; D058986:Phosphodiesterase 5 Inhibitors / Q000032:analysis* / Q000627:therapeutic use; D010879:Piperazines / Q000032:analysis / Q000627:therapeutic use; D011687:Purines / Q000032:analysis / Q000627:therapeutic use; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000032:analysis / Q000627:therapeutic use; D000068581:Tadalafil; D014481:United States
chemical_list: D002243:Carbolines; D004366:Nonprescription Drugs; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068581:Tadalafil; D000068677:Sildenafil Citrate
keywords: Erectile Dysfunction; Herbal Medicine; Phosphodiesterase Type 5 Inhibitors; Sildenafil