Now that everyone has danced all around your original question about the history of Mamajuana: My wife, a 16 year resident of Las Galeras in Samana, tells me that when she got here in 1986, she only found Mamajuana in Las Galeras and nowhere else on the island. It was truly a local medicine for the flu, "la Grippe," and the mixture contained bits of trees, roots, herbs and spices; the same recipe that is sold today by a local man in Las Galeras named "Negro." Rum and honey is the concoction's liquid elixir although a number of variations have emerged at various locations on the island.
Although primarily a "medicine" for the flu, many hucksters tout it's sexual powers to gullible tourists, "powers" that are no more evident than the relaxed feeling (and lowered inihibitions) one gets after a shot or two of alcohol.
Hope this helps.