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How Products were Selected:

Products selected represent those commonly sold and/or available nationally in the U.S. purchased products on the open market through retail stores, on-line retailers, catalogues, or multi-level marketing companies. Products were not accepted directly from manufacturers.

Testing Methods:

L-Arginine products were tested for their total L-arginine content, while Yohimbe products were tested for their yohimbine or total yohimbe alkaloid content and Epimedium products were tested for their icariin content. All products were tested for possible contamination with lead or PDE-5 inhibitors.

Analyses for L-Arginine were performed using LC/MS.

Analyses for Yohimbe (and Yohimbine Alkaloids) and Epimedium sp. marker compounds were performed using HPLC.

Analyses for the presence of anti-impotence drugs (PDE-5 and analogues) were performed using HPLC/MS/MS. Compounds tested for:
Acetildenafil (hongdenafil)
Benzamidenafil (xanthoanthrafil)
Dimethyl sildenafil (aildenafil)
Dimethyl sildenafil thione (sulfoaildenafil)
Homosildenafil thione (sulfohomosildenafil)
Hydroxyacetildenafil (hydroxyhongdenafil)
Hydroxyhomosildenafil thione (sulfohydroxyhomosildenafil)
Piperadino acetildenafil (piperadino hongdenafil)
Piperadino vardenafil (pseudovardenafil, piperidenafil)
Sildenafil thione (sulfosildenafil)
N-Butyl Tadalafil

Analyses for lead were performed using ICP-MS (Inductively Coupled Plasma-Mass Spectroscopy).

Disintegration of non-chewable, non-capsule, non-enteric coated and non-time release formulations was analyzed by utilizing USP (United States Pharmacopeia) <2040>.

Products failing to meet any Passing Score were re-tested in a second independent laboratory using similar methods and instrumentation. may modify or use other appropriate test methods if necessary to test special product formulations.

Passing Score: *
To achieve a "Pass" in the testing, a product had to meet applicable criteria:

L-Arginine Products:

Must meet 100% of label claim for L-arginine (free base) or L-arginine complexes (e.g. arginine hydrochloride).

Yohimbe Products:

Products containing Yohimbe must be made from the Yohimbe "bark" and meet 100% and not exceed 135% of label claim for identity and quantity of Yohimbe and have a minimum of 0.27% of yohimbine and 2.7% total alkaloids (Expanded German Commission E).

Epimedium Products:

Products containing Epimedium must be made from Epimedium aerial parts (above ground) and meet 100% of label claim for identity and quantity of Epimedium spp. and have a minimum of 1% icariin (Pharmacopeia People's Republic of China; English Edition, 1997).

All Products:

  1. Not exceed California Prop 65 levels for lead contamination in a recommended daily serving, i.e., contain less than 0.5 mcg of lead per daily serving with an additional allowance of 1.0 mcg for supplements containing 1,000 mg/day or more of elemental calcium and 0.5 mcg for supplements containing specific other minerals.** For supplements not marketed for use by children, provides an additional allowance of 0.5 mcg if containing 250 to 499 mg/day of elemental calcium, or 1.0 mcg if containing 500 to 999 mg/day of elemental calcium, and an allowance of 0.5 mcg if containing one whole herb (not extract) ingredient or 1.0 mcg for two or more whole herb ingredients. If a maximum recommended daily serving is not defined, a daily serving size will be determined and applied by CL.
  2. Meets recommended USP parameters for disintegration for dietary supplements (excluding capsule, enteric coated, chewable and time-release products).
  3. Must not contain any amount of sildenafil citrate, tadalafil, and vardenaifil or other PDE-5 inhibitors.
  4. Meet FDA labeling requirements.
A "Pass" was based on meeting the above criteria in either the first or second rounds of testing.

* Passing scores allow for specific margins of technical error associated with each analysis. reserves the right to disqualify a product at any time from passing its testing if it considers such product to present a safety risk or to provide misleading or inaccurate information in its labeling.

** Based on State of California's Prop 65 lead limit. California requires supplements exceeding this limit to bear a warning label regarding lead.

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