Both the Testosterone Protocol and Blood Flow Protocol can have an effect on libido. Testosterone Protocol users generally report an increase in energy, better sleep and improved gym performance as well as increased confidence and assertiveness. Blood Flow Protocol users report overall increased libido and blood flow during performance.
If you're looking for something to improve your T levels then Testosterone Protocol is the best option, if you're just looking for increased libido/blood flow then you should go with Blood Flow Protocol. They share some aspects such as improved libido, but the main result of Testosterone Protocol is optimized T levels (which may have an effect on libido for some users).
More information on these protocols here:
https://www.maximustribe.com/blood-flow-protocol
Some patients take both together, as they work together synergistically. You can always consult with your clinician once you sign up and they can assist you further with deciding which protocol is the best option for you.