Can you afford to help your kid start a business?

Amazon. Chipotle. GoPro. These household-name businesses were launched thanks to investments by the founders’ parents. But parents also have sunk plenty of money into their offsprings’ doomed enterprises, sometimes endangering their retirements and family relationships in the process.

Certified financial planner Jon Ten Haagen of Huntington, New York, had a retired client who against his advice gave $100,000 — most of her savings — to her son to start a restaurant. The business failed within a year, and he has yet to pay any of the money back, he says.

“She’s just getting by at this point,” Ten Haagen says.

Don’t offer money you can’t afford to lose

Parents usually want their kids to succeed, and many are accustomed to sacrificing to help make that happen. But parents shouldn’t be mislead about the risks, financial planners say.

“This investment is going to be concentrated, illiquid, and with high risk of total loss,” says Hui-chin Chen, a CFP in Arlington, Virginia. “If it fits in the parent’s portfolio and does not jeopardize their retirement, then it’s something both sides may consider.”

Parents whose finances can’t withstand losing the money should focus on providing other kinds of support, such as helping draft a business plan or pointing them to the nearest Small Business Development Center.