Instagram and Facebook have bowed to pressure to remove content from a Northern Ireland-based charity offering help to people with unwanted same-sex attraction.
The social media platforms told CNN that they would remove posts from the Core Issues Trust that advertise or promote 'conversion therapy', a form of therapy that can help to diminish unwanted homosexual feelings.
The decision follows a social media campaign by activists to have the Core Issues Trust banned.
"We don't allow attacks against people based on sexual orientation or gender identity and are updating our policies to ban the promotion of conversion therapy services," Tara Hopkins, Instagram's public policy director for Europe, the Middle East and Africa, told CNN.
"We have removed violating content from @coreissuestrusttv. We are always reviewing our policies and will continue to consult with experts and people with personal experiences to inform our approach."
A spokesperson for Twitter told the news outlet that the platform already had policies in place to block posts promoting conversion therapy.
But the spokesperson added that it was "working to make the training decks more clear so that team members have a wide variety of examples to refer to and our enforcement of this is consistent and scaleable globally".
There have been concerted efforts worldwide to ban therapeutic choice for people struggling with unwanted same-sex attraction.
In May, the UN's independent expert on sexual orientation and gender identity, Victor Madrigal-Borloz, called on countries around the world to ban conversion therapy.
Elton John and Stephen Fry are among the public figures in the UK supporting the calls for a ban.
The UK Government recently said that it wanted to "understand the problem, the range of options available and the impact they would have" before making any decision on conversion therapy.
"Conversion therapy is a very complex issue. There are a wide range of practices which may fall within its scope and we want to ensure we have a thorough understanding of the situation in the UK to inform an effective approach," the Government Equalities Office said.
It added: "As we have said previously, we are not trying to prevent LGBT people from seeking spiritual support from their faith leader or others in the exploration of their sexual orientation.
"The UK Government is committed to ensuring all citizens feel safe and are protected from harm. This is why we will work to deepen our understanding and consider all options for ending the practice of conversion therapy."