Welcome to the forum,
The gents above know best but I was actually wondering if there is one specific tool as opposed to a tool kit.
I offer the female side of the limited perspective. A lot of time libido can be tied to other things so as the gents suggest, a little more information can really help to direct you toward some well informed recommendations that may make things easier across the board.
Before I make any recommendation (because I think the ones you have are great) I would ask you to tell us more about yourselves (you and GF) and your general dynamic. This is more to direct you to the best product to start with.
In the meantime I’m adding some links that might be able to assist you and several journals in the Men’s forum can really get you started.
What Pheromones Can Do And What They Can’t Do
How do I know if I am getting hits !!
Great Intro Pack suggestion for Males
Journals with great content and perspective (hetero specific):
Mobocaster
CelticPrince
Justintime469