You may wish to re-examine lycanthropy. I understand that a time of the month is an issue but per the AD&D 2e Monster Manual:
Lycanthrope, General: "A distiction must be made between true lycanthropes and infected lycanthropes. True lycanthropes are those to whom lycanthropy is a genetic trait; they breed with other lycanthropes and produce baby lycanthropes. Only true lycanthropes can infect others with lycanthropy. Infected lycanthropes are those whose lycanthropy results from being wounded by a true lycanthrope."
Contracting lycanthropy: "True lycanthropes have complete control over their physical states; they are not affected by darkness, phases of the moon, or any of the other situations which traditionally affect infected lycanthropes." [emphasis added]
True lycanthropes essentially retain control of themselves, including personality, form and actions.
The MM link above has general guidelines for creating new lycanthropes, a Curse of Lycanthropy spell that could easily be modified to inflict true lycanthropy and don't forget (cursed?) magic items -- these could bestow all the effects of true lycanthropy without the "infection" side effects (per a slightly modified ivory "Amulet of the Beast".)
Amulet of the Beast: Two versions of the amulet exist: one made of silver, the other of ivory. Both show the image of a wild, wolflike beast, which is bonded in chains. Each amulet is round, and has a small hole at the top for threading a cord or chain.
Ivory: The ivory amulet, when touched to a character, gives its victim the symptoms of lycanthropy. (It has no effect on creatures who are already lycanthropes.)
Most ivory amulets produce "werewolves," but a given amulet could mimic any form of the disease. The amulet is magically attached to its owner until a remove curse spell is cast. Even then, the victim must save vs spells successfully to be free of the amulet. Not every victim desires such freedom, however. When the amulet is gone, so are the symptoms of lycanthropy.
The silver version is also interesting:
Silver: The silver amulet functions only when worn by a lycanthrope. As long as the creature carries the amulet somewhere on his person, his lycanthropy is supressed. Even a true lycanthrope cannot change shape while holding this silver amulet. No magical force prevents the item's removal, but the owner may protect it from theft by other means.
I would also suggest looking at this Wikipedia entry on D&D lycanthropes for a list of other official lycanthropes that are available besides just those in the MM.
A personal favorite of mine for true lycanthropes is Ravenloft 2e Campaign Setting Loup-Garou, essentially a beefy (STR 18/00) werewolf.
Full stats and other information available from the link. Note that Loup-Garou can
assume man, man-wolf or wolf shape essentially at will.
Combat: The tactics and weapons that a loup-garou employs in combat depends wholly upon the shape that it employs. The creature needs a full round to change from one form to another.