June Dobbs Butts, a sex researcher and therapist who argued for greater frankness among African-Americans about issues that were often considered taboo, died on May 13 at a care facility in Johns Creek, Ga. She was 90.

Her daughter, Florence Johnson, said she died a few days after having a stroke.

Dr. Butts was by many accounts the first African-American to train and practice at William Masters and Virginia Johnson’s famed institute in St. Louis, and she brought their modern, uninhibited view of sex therapy to black patients in the 1970s. A 1980 profile in The Washington Post, published after Dr. Butts had established her own practice in Maryland, said that “at Masters and Johnson, all of her patients were white; now 90 percent of them are black.”

Dr. Butts advocated honest discussion of topics like masturbation, bisexuality and gender reassignment. She hosted a short-lived radio call-in show in Washington and wrote articles for magazines like Jet and Ebony and a column, Our Sexual Health, for Essence in the late 1970s.

Not everyone was receptive to her ideas at first.

“When I first wrote the column, I sent a copy to one of my sisters,” Dr. Butts told The Post in 1980. “I didn’t hear anything. Finally I asked her what she thought. You know what she said? ‘Well, to tell you the truth, June, it turned my stomach. I didn’t think black women would write about things like that.’ ”