In general, Yes; some compounds may act as aphrodisiacs (in addition to being pro-erectile agents, usually seen as a different category). Not all compounds touted to increase libido do, but quite a few herbs have shown to be effective in increasing libido and sexuality.
A wide variety of herbals and related compounds are marketing for increasing sex drive and appetite. These aphrodisiacs are usually herbs that have been used traditionally for increasing 'vitality' or male 'sexuality' and are being investigated scientifically for their roles in either fighting age-related sexual decline or possibly to fight andropause (a term used to mimick menopause, describing the decline of vitality and testosterone seen in aging men).
No sufficient in vitro (in glass) test will tell if a compound is a good aphrodisiac, studies done on the subject matter must be in vivo (in life); usually a rat model.
In general, rats are given a compound and then their sexuality is observed. Pre-sexual signs (anorectal sniffing of female rats, popping little rat boners) indicate libido whereas the frequency of sexual encounters (mounting, ejaculation latency, time to re-mount or time between ejaculations) indicate virility. These studies, if they note an increase in rat sexuality, serve as the starting evidence for what works as an aphrodisiac.
It should be noted that rats can either be chemically or physically castrated or they can be otherwise healthy; this is an important distinction, as castracted rats serve as a model for human hypogonadism (chemically usually mimicks central hypothalamic hypogonadism, and crushing the poor rat testicles mimicks peripheral, or testicular, hypogonadism). Otherwise healthy rats would be a good model for otherwise healthy humans.
After rat studies, compounds are sometimes tested in humans for their aphrodisiac effects. The results are usually obtained via self-report survey about how sexual the subjects felt during the trial period.
Compounds that have been touted or otherwise shown to increase Aphrodisia and Sexual appetite are currently listed and updated on our categorical page on Aphrodisiac compounds.