Sildenafil citrate (Viagra) impairs fertilization and early embryo development in mice  David R.J. Glenn, M.R.C.O.G., Neil McClure, F.R.C.O.G., S. Louise Cosby, Ph.D., F.R.C.Path., Michael Stevenson, B.Sc., Sheena E.M. Lewis, Ph.D.  Fertility and Sterility  Volume 91, Issue 3, Pages 893-899 (March 2009) DOI: 10.1016/j.fertnstert.2007.12.014 Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions

Figure 1 (a) Effect of sildenafil citrate on fertilization rates (27 control mice, 29 test mice). (b) Effect of sildenafil citrate on embryo numbers and cleavage at day 2 (14 control mice, 14 test mice). (c) Effect of sildenafil citrate on embryo numbers and cleavage at day 3 (19 control mice,19 test mice). (d) Effect of sildenafil citrate on embryo numbers and cleavage at day 4 (21 control mice, 21 test mice). Violet bars = control embryos; blue bars = embryos formed from sperm where male mice had had oral dose of sildenafil citrate citrate (0.06 mg/0.05 mL, equivalent to 100 mg human oral dose). Values are mean ± SE. ∗∗P<.001. Fertility and Sterility 2009 91, 893-899DOI: (10.1016/j.fertnstert.2007.12.014) Copyright © 2009 American Society for Reproductive Medicine Terms and Conditions