Libido enhancers actually go hand in hand with herbal male enhancement products because herbal male enhancement products are designed to do three things to enhance your sex drive and sex acts that are often lessened by stress, perhaps one more than the other, depending on the product you end up choosing:

1.) Enhance the male libido, or sex drive. They make you crave sex more in other words.

2.) Increase the overall size of your erections, making for a better feeling of friction and therefore pleasure for both of you during intimacy.

3.) Allow for more powerful sexual climaxes, or orgasms due to their innate enhancement of the actual sensation of sex. They essentially act as a magnifier of sexual sensations and actual senses that make up the orgasmic factor of sex. They actually can trigger hormones and endorphins, which are all part of the intensity felt by a man when he comes (or cums, however you prefer!)

So, you see all male enhancement products are designed to increase and enhance the libido, since there are so many factors - stress being the main one that can literally suck the desire to have sex right out of your life.  See Libido Enhancers for specifics.