This is very frustrating for you and I wonder does your partner think that he has a low sex drive? It may be the case that the current frequency of intercourse is adequate for him. You need to have some preliminary discussion with each other about this matter because if he doesn’t see this as a problem then you may be facing into further frustration. Leaving those preliminary considerations aside there are many causes for low sex drive. It could as you have suggested be hormonal in origin and your partner may have low circulating levels of testosterone. This can be established by measuring the level of testosterone in his blood. If he is exhausted from work or lacking in physical fitness this could also account for his low sex drive. Could he be depressed? Depression can flatten a person’s libido or sex drive. Is your partner taking any prescription drugs? Could he be using cannabis, cocaine or alcohol, which have all been shown to depress libido? Maybe your partner is preoccupied with work or other issues that is displacing his interest in sex. Finally maybe your partner is becoming complacent. The present situation can only be resolved by discussing matters and then taking whatever steps are necessary to solve the problem.