** Shares of McPherson's MCP.AX fall 7.7% to A$0.36, their lowest since March 2009

** Stock set for worst trading session since late August

** Aussie health and wellness products supplier expects H1 FY 25 underlying EBITDA to be significantly below yr-ago's A$7 mln ($4.5 mln)

** Says sales from core brands grew by 1% in first four months of FY25

** Trading vol of 300,000+ shares is nearly 7x the 30-day avg

** McPherson's down 40.5% YTD, including current session's moves ($1 = 1.5454 Australian dollars)

(Reporting by Nikita Maria Jino in Bengaluru)

((Nikita.Jino@thomsonreuters.com;))