Units are not standardized by volume for conversion. In other words 10U insulin is not the same as 10U HGH in ml's or cc's. So there isn't a standard conversion factior,it depends on the substance.As far as HGH goes,6mg of powder makes 18U,the volume will depend on the amt of dilutent.In other words,1mg=3U. That's how the Serostim is dosed anyways,I've never used the Lily product. But 5mg's probably is 15U if I had to guess.