May 21 (Reuters) - Two separate asset-management firms announced the debut of exchange-traded funds (ETFs) on Tuesday, both which are designed to give investors exposure to stocks like Eli Lilly & Co and Novo Nordisk which are pioneers in developing new anti-obesity drugs.

Amplify ETFs said its Amplify Weight Loss Drug & Treatment ETF will track the VettaFi Weight Loss Drug & Treatment Index, while the Roundhill GLP-1 & Weight Loss ETF will be actively managed by the team at Roundhill Investments.

The two products take slightly different approaches to building a portfolio around the new category of medications to treat obesity, known as glucagon-like peptide-1 or GLP-1 drugs. Roundhill plans to focus squarely on pharmaceutical companies developing new drug therapies, while Amplify will include a 30% weighting to companies involved in related businesses, such as manufacturing, analysis or distribution of these medications.

The number of ETFs targeting this booming segment of the pharmaceutical market appears to be exploding. In early 2020, Janus Henderson closed its own obesity-focused ETF, leaving investors with only broader pharmaceutical or healthcare fund options. But last month, Tema, another niche asset manager, re-branded and re-launched a five-month-old ETF investing in stocks targeting cardiovascular and metabolic health. The more narrowly focused Tema Obesity and Cardiometabolic ETF has added more than $63 million since then.

It remains to be seen how long investors remain enthusiastic about ETFs tied to this particular trend, however. In the first four months of this year, ETFs designed to appeal to investors keeping tabs on trends like cybersecurity, working from home, pet care or cannabis have recorded outflows of $2.4 billion, compared with outflows of $4.9 billion in 2023. (Reporting by Suzanne McGee in Providence, Rhode Island Editing by Matthew Lewis)