I have experimented with it for dreaming purposes. After about 3 days of smoking 2x day, it triggered a lucid dream (a real lucid dream- not the "I know I'm dreaming dream"- the "It's just like waking life dream... except I can fly"). It has no impact on me as an aphrodesiac and it never got me high er anything.

very strong combination: damiana, passionflower, and weed.

but as for the herb itself:

Damiana is used as a general tonic for the nervous, hormonal, and reproductive systems. It has an ancient reputation as an aphrodisiac. Some claim damiana tea has a relaxing effect not-unlike low doses of cannabis. Others argue that Damiana has no active ingredients, and that its medicinal reputation is based on damiana tonics from the late 1800s which were inactive, or contained enough alcohol and/or coca to produce unrelated effects EROWID, herb vaults

I have taken it as a tea and had noticable affects when mixed with other herbs. It may have a cross tolerance working with certain staple herbs, as I have noticed that too much damiana in any mix can kill the effects of the other entheogen herbs. Even good quality hash may be ruined by this dulling effect. Even sex when I try to load up on this herb as if I were taking viagra never has worked for me even though people out there swear it is a natural sexual stimulant on par with the blue pill. I think it's ability to change the feel of several other ethnobotanical agents is worth investigating. or, grow this plant and develop a relationship with it (something I have not done with damiana yet, but have had great success with other herbs with subtle or difficult to understand characters--datura, Lemon Balm, morning glory, salvia, galanga, etc) and see what you can learn from that relationship. Lemon Balm or melissa is a great lucid dreaming aide--a satchel of it under the pillow is all it takes or a tea before bed--also a minor sedative.