Even President Donald Trump doubted Elon Musk’s ability to cut $1 trillion in federal spending.

“Was it all bulls--t?” Trump asked advisers of Musk’s cost-cutting under the Department of Government Efficiency (DOGE), the Wall Street Journal reported in a behind-the-scenes look at the pair’s working relationship.

Musk pledged to cut $1 trillion from the federal budget but ultimately managed to cut only $170 billion, according to DOGE’s own calculations, which have themselves been called into question.

Elon Musk with President Donald Trump during a press briefing to mark the end of his role at the Department of Government Efficiency. Kevin Dietsch/Kevin DIetsch/Getty Images

Trump was often at odds with Musk. The billionaire’s eccentric humor often confused the president, who told his aides that Musk was “50 percent genius, 50 percent boy,” the Journal reported.

Musk announced his departure from the White House this week after a contentious tenure marked by mass layoffs, reversals, and court setbacks.

Musk frequently butted heads with Trump’s staff, according to the Journal, and it escalated to the point that Trump asked White House Chief of Staff Susie Wiles to step up and better manage Musk. Trump didn’t even know the exact moment Musk was leaving DOGE until Musk himself posted it on X.

Musk has also been less forthcoming with money after giving Trump $288 million during his most recent campaign, the Journal noted. He told Trump’s advisers this year that he would give $100 million to groups controlled by the president’s team before the 2026 midterms. But as of this week, the money hasn’t come in.

Tesla CEO Elon Musk announced his departure from the White House this week after fulfilling only 17 percent of his goal to slash federal spending. Kevin Dietsch/Kevin Dietsch/Getty Images

Musk’s four-month stint at the White House also included frequent drug use, according to a bombshell New York Times report. Musk told associates he took ecstasy and magic mushrooms and was a regular ketamine user, which led him to develop severe bladder problems. He also carried a pill case with Adderall, the Times reported.

In the wake of the Times report, Republicans and Democrats alike have connected Musk’s drug use with his erratic behavior—including his Nazi-like salute during Trump’s inauguration and mumbling interviews.

President Donald Trump frequently butted heads with Elon Musk, both publicly and privately. ALLISON ROBBERT/Allison Robbert/AFP via Getty Images

Musk’s departure from the Trump administration is also fueled by his rapidly plummeting Tesla sales. “I have to get some heat off me and my companies,” he has said privately, the Wall Street Journal reported. The electric car company’s net income dropped by 71 percent in the first quarter.

Trump, however, said Musk won’t stay away entirely. “Elon is not really leaving,” Trump said on Friday. “He’s going to be back and forth.”