Instagram has introduced new measures to reduce suicide and self-injury content being accessed by users, following pressure from parents of suicide victims who say it contributed to their children's deaths.
The social media company is promising to "make it harder for people to search and find self-harm content".
It comes ahead of a meeting today between Instagram boss Adam Mosseri and Health Secretary Matthew Hancock.
Mr Hancock is expected to tell the worldwide head of Instagram that the company should treat suicide and self-harm images with the same gravity as terrorist-related posts.
This week, suicide prevention minister Jackie Doyle-Price warned that this content "normalised" self-harm and had the effect of "grooming people to take their own lives".
Sky News spoke to a victim's parent, who said messages she accessed through Instagram acted as "encouragement to get worse".
Zoe Watts, a talented gymnast, took her own life aged 19 in March 2017. Her father Keith blames failings in the health service, but also says messages and images his daughter accessed on social media were a contributing factor.
He told Sky News: "I've seen some of the images of young girls with some pretty bad slashes on their arms and there's kind of a bit of a brag about it.
"Zoe printed off images of emaciated girls. The one message that rings in my mind was message saying that 'your grumbling stomach is actually an applaud for not eating.'
"They are very vulnerable at that time and when they start reading these messages it becomes an encouragement for them to get worse."
He added: "To try to follow what somebody has been doing over a long period of time through social media, through hashtags and looking at websites from a parents' point of view is an impossible situation, but from the social media company's point of view they can put in place systems that can at least try to calm that down and restrict access."
A spokesperson for Instagram told Sky News: "We want to be sure we're getting this right and we have started a full review of our policies, enforcement and technologies around suicide and self-injury content.
"Whilst we conduct this review, over the past week we have had a team of engineers working round the clock to make changes to make it harder for people to search for and find self-harm content.
"We have further restricted the ability for anyone to find content by searching for hashtags and in the Explore pages and we are stopping the recommendation of accounts that post self-harm content.
"In addition, from this week people will start to see sensitivity screens appear over self-harm related content that is permitted under the guidelines."
Dame Sally Davies, England's Chief Medical Officer, says social media companies need to be more proactive and immediately introduce a voluntary code of conduct.
Dame Sally is also introducing more wide-ranging guidance on how parents can cut down children's screen-time and police their activities online.
The first official advice from the UK's top doctors is that families should ban phones at bedtime and keep them away from the dinner table. Screen-free meal times are encouraged in order to enjoy face-to-face conversation between adults and children.
Screen users are also advised to take a break after a two of hours and do something more active for a while. The top doctors also suggest parents to talk to children about sharing photos and information online.
Dame Sally said: "Time (Frankfurt: A11312 - news) spent online can be of great benefit to children and young people, providing opportunities for learning and skills development, as well as allowing young people to find support and information.
"But we need to take a precautionary approach and our advice will support children to reap these benefits and protect them from harm."
Some research included in the review, which was carried out by a team at University College London, has found a link between those who use screen-based activities more frequently and over longer periods and mental health problems.
But it is not possible to conclusively determine if screen time can cause these issues.
:: If you feel emotionally distressed or suicidal call Samaritans for help on 116 123 or email email@example.com in the UK. In the US, call the Samaritans branch in your area or 1 (800) 273-TALK.