Movie stars often aren’t shy when it comes to using their clout to help shed light on worthy causes, but few have the platform of Bollywood superstar Aamir Khan, whose weekly talkshow “Satyamev Jayate” (Truth Alone Prevails) recently completed its third season on 21st Century Fox’s Star India network and Indian national broadcaster Doordarshan.

Khan, the star of “Dhoom: 3,” India’s all-time highest box office earner, at $88 million, also starred in “3 Idiots,” the locally produced B.O. champ that “Dhoom: 3” toppled, and was the star and producer of 2001’s “Lagaan: Once Upon a Time in India,” which earned India’s last Oscar nomination in the foreign-language category. All three films were hits in China and Japan — non-traditional markets for Indian cinema.

On his TV show, Khan focuses on social issues like domestic violence, “honor” killings, sexual abuse and female feticide in a nation in which corruption and superstitious practices are endemic. Before starting the TV show, he got some advice from those looking to protect his box office viability: Don’t do it.

“A lot of people told me there would be an adverse effect on my film career because I am picking very sensitive topics and showing a mirror to society that sometimes society doesn’t want to see. (They said), ‘You may rub people the wrong way,’ ” Khan says.

But the actor forged ahead. “This was something I really wanted to do, and I didn’t think of the consequences,” he says. “As it turned out, it’s had a good impact, and a lot of people love the show.”

“Satyamev Jayate” topped its Sunday 11 a.m. timeslot across India, trended on Twitter, was the top Indian search on Google Trends, and its website crashed due to heavy traffic.

Khan says that to draw audiences in to each episode, he mixes journalism with nonfiction storytelling, and that promos never feature any potentially off-putting subjects.

“The reason I decided not to reveal anything on any topic (beforehand) is because the topics are really heavy, serious and sometimes dark,” Khan says.

Rather, he approaches a subject from a point of general agreement.

For example, on the issue of female feticide, he built up the featured women as mothers first, since mothers are revered in Indian culture, and only after that explains that the women are forced into the age-old practice of aborting pregnancies that would produce female babies.

Many of Khan’s movie choices, too, reflect his social conscience. The BAFTA nominated “Rang de basanti” examined government corruption; “Like Stars on Earth” (Taare zameen par), which Khan also directed, tackled the subject of dyslexia; and though “Dhoom: 3” was a Chicago-set action film, “3 Idiots” took a humorous look at the deficiencies in India’s university system.

Khan’s next film, “PK,” will be released Dec. 19 in the U.S. Directed by “3 Idiots” filmmaker Rajkumar Hirani and produced by Disney’s Indian production unit UTV, it may be his most socially targeted work yet, though typically, he’s revealing little. The film is rumored to revolve around an outsider who asks questions that make residents think about things in a new way.

Khan says only that his starring role in the picture is among the most challenging of his career.

“I feel that in the last 25 years, all the characters that I’ve played are on one side, and this one is on the other,” he says. “It’s a story I love, and what it is saying at its core is important. And like Rajkumar Hirani’s earlier films, it is a drama, but the vehicle is humor.”

Teasers for the film reveal a bug-eyed Khan arriving “Terminator”-style at an Indian village, buff and naked, with only a radio covering his modesty. The teaser has set off a frenzy of speculation among Bollywood fans worldwide.

“I’m using my status as an actor hopefully in a positive way,” he says.

Then, considering his dual role as a TV host, he adds: “I’m not doing (these things) because I’m an actor. I’ve devoted my time in a different way because that’s the kind of human being I am.”