I dont understand why exactly your girlfriend is afraid of substituting? When I took my drug test it was the easiest thing I had ever done. I had the mini bottle of clean pee in my underpants snuggly, keeping it warm, and then they let me into a bathroom all by myself where I shut and locked the door, and gave me 4 minutes to pee. Batta bing batta boom, it was surpirsingly easy. Theres no reason to be nervous, and the only way they would find out is if they are watching you pee, which youve already stated they aernt gonna do it. As this girls man, I order you to build up her confidence, especially if this is that important! Kidding...

All that aside, I have never heard of these 'syrups' that your speaking of. I dont know whats in them or how they work. Are you sure it was even the syrup product that attributed to your success the first time? Did you take any others actions? I think I read it makes your pee glow almost and look unnatural, so you may want to think twice about using that especially if your passing the at home tests. Here is what I recommend. Either suck it up, overcome FEAR and substitute the pee so you KNOW you will pass, and I know she knows that that is the most sure way of passing this test, or take the chance and go in with your own pee, WITHOUT taking the syrup. I think using your own pee with your amount of preperation and lack of smoking would be the best way if your gonna use your own pee, because that syrup is an unfamiliar product your using right now and you are unaware of what results it might give. That is just my opinion, wait and see what the more experienced users have to say about it.