• A Danish intelligence official said Putin was taking thyroid-cancer drugs in February 2022.
• He told Danish media the drugs can cause “delusions of grandeur” and may have warped his thinking.
• Rumors of Putin being ill have abounded, but experts say they’ve yet to see credible evidence.

Russian President Vladimir Putin was taking thyroid-cancer drugs that may have warped his decision-making when he decided to invade Ukraine, a senior Danish military-intelligence official said in an interview.

The claim was reported by the Danish newspaper Berlingske based on an interview with the head of the Russia analysis team for Denmark’s national defense intelligence agency, Forsvarets Efterretningstjeneste (FE).

The official was referred to only by his first name, Joakim, citing security reasons. He told the newspaper that Putin was taking hormones to treat thyroid cancer in February 2022, and that it likely affected his mental capacity.

He said “delusions of grandeur” are a known side effect of the type of hormone treatment that he believes Putin was on at the time.

“It’s not something I can say for certain, but I think it did affect his decisions when he launched the war in Ukraine,”  he told the newspaper.

He did not go into details about the specific hormone treatment but added that it would also have contributed to the “moon-shaped face” Putin had at the start of the year.

He did not give details of how his agency came to believe that theory.

Speculation has abounded since the start of the invasion that Putin is sick, based on Russian media reporting, interviews with former Western officials, and claims by Ukraine.

None have been backed up by clear evidence, and many experts have been hesitant to draw strong conclusions.

Tabloid media and a variety of commentators have also pointed to Putin’s bloated-looking face when discussing his health. 

James Clapper, the former director of national intelligence, told Insider in May that the bloating did raise questions about whether Putin was receiving a medical treatment that would cause swelling. Clapper, however, said he doubted that the US intelligence community knew for sure if the Russian leader was sick.

Jeffrey Edmonds, a former director for Russia on the National Security Council and an ex-CIA military analyst, also spoke to Insider in May and said that he hadn’t seen anything “truly credible” to suggest that Putin was seriously unwell. 

The Danish official also spoke to Berlingske in guarded language, asserting that reports of Putin having had thyroid cancer were “definitely a good bet.”

He said that his agency does not believe that Putin has a terminal illness.

Another theory is that Putin is suffering from Parkinson’s disease, with some citing a video showing Putin gripping onto a table during a meeting with the Russian defense minister Sergei Shoigu.

John Hardy, a neurogeneticist at the UK Dementia Research Institute, dismissed these claims while speaking to the German public broadcaster Deutsche Welle in March. “No sign of parkinsonism in my view,” he said.

Joakin said his agency has a different theory for the table-gripping: that Putin is suffering from chronic pain after a series of falls and accidents.

“This is chronic pain that he has suffered from for quite some time now,” he told Berlingske. “That’s why he tends to sit and grab things tightly. It’s to ease the pain.”

A retired US brigadier general and a former defense attaché to Russia, Kevin Ryan, told Insider in May that the start of the Ukraine war could not be attributed solely to Putin or his health.

“Of course everyone is going to die, but I don’t think this war is the creation of only Putin,” Ryan said, adding, “His death might affect its course, but the ruling circle which supported him will still be there.”

The head of the UK armed forces said in July that theories about Putin being badly ill or at imminent risk of losing power were likely due to “wishful thinking” by his enemies.