‘Am I 68? 69?’ Irvine Welsh on growing old, getting clean, bashing out his new novel – and flirting with guns

Three decades after he channelled his heroin addiction into the cult classic Trainspotting, the Scottish author has discovered the joys of yoga, breathwork and standing desks. But is he quite as ‘Zen’ as he claims?

Fitness influencers linked to wellness brand helping run illegal steroid market on Telegram

Ambassadors for Gencore Global directed followers to Telegram channels promoting steroids, prescription medicines and experimental peptides

NHS staff battling wave of food supplement disinformation

Exclusive: Cancer charity says dispelling falsehoods gleaned from social media is now routine task for clinicians

Is it true that … we should all be taking creatine?

The supplement is a proven sports performance enhancer, but research is ongoing and for most people it’s an optional extra, not an essential

‘They’ve invented a spurious pseudo-disease’: why are so many men being told they have low testosterone?

Social media influencers and booming men’s health companies are pushing the hormone as an answer to all ills. But is ‘low T’ really problematic – or something created to sell men a cure to a problem they don’t have?

‘Traceability is vital’: labs test thousands of unregulated substances amid peptide craze

Experts warn consumers of unknown risks as one lab says about a third of samples fail basic quality checks

Trying to conceive? Welcome to the worry-filled world of ‘trimester zero’

An army of ‘pregnancy prep’ influencers is offering would-be parents everything from sensible advice to quackery and questionable supplements. What’s really needed?

My teenage daughter’s OCD keeps getting worse. What can I do?

Cognitive behavioural therapy may help her to cope with her anxiety and learn that she doesn’t need to respond to intrusive thoughts

What are peptides, are they safe and is there evidence to back up the hype?

Influencers and athletes are among those claiming substances can help with injury repair, weight loss and angi-ageing

Medicines watchdog to investigate UK peptide clinics over health claims

Exclusive: Guardian investigation finds several clinics making potentially unlawful claims about benefits of unregulated therapies

Full-blown agony: my battle against the mysterious pain of cluster headaches

They can hurt more than broken bones or pancreatitis. But with the right drugs and therapies, relief is possible from this debilitating and often misunderstood condition

New antibiotics hailed as ‘turning point’ in treating drug-resistant gonorrhoea

First new treatments for sexually transmitted disease in decades approved by US Food and Drug Administration as number of cases worldwide surge to 82m

She was pregnant and addicted to fentanyl. Getting to keep her baby saved them both

A baby is born in withdrawal every 18 minutes in the US, and most end up in foster care. At centers like Maddie’s Place, mothers stay with their infants – and leave together, in recovery

‘The pressure to get your old body back is immense’: the new mothers driven to weight-loss jabs

The NHS warns against using GLP-1s while breastfeeding – for the baby’s sake as well as the mother’s. But how much does that count when they’re so readily available and there’s so much pressure to ‘bounce back’?