Imperfect capital markets and commitment problems impede lumpy human capital investments. Labelled loans can alleviate both constraints, but little is known about their effectiveness in practice. We draw on a cluster randomized controlled trial in rural India to provide the first evidence that labelled microcredit is effective in increasing take-up of a lumpy human capital investment, a safe toilet. Testing predictions from a theoretical model provides novel evidence that loan labels influence household borrowing and investment decisions. Not all loans are used for sanitation investments, suggesting that loan labels offer a soft commitment incentive.