Gross product sales increased 21% to US$4mln against US$3.3mln in the same time in 2015, the life sciences group said.
Despite strong competition, it gained market shares in both the UK and the USA, where the product is now found in Walgreens, CVS and Rite Aid.
The firm also reported its first sales in France, while Vamousse was included in the NHS Minor Ailments Scheme in the UK.
The period also saw the group enter the animal health market which, it says, represents a large and growing opportunity and the group made first sales of its animal health products, with the first three now being actively promoted.
Looking ahead, chief executive Bruno Jactel said the firm expected the second half to be stronger than the first as we enter the "back to school" period for Vamousse sales and it "actively promotes" its animal health portfolio.
But he added the rate of growth will be lower than previously anticipated and revenue and net loss for the full year will be below market expectations - mainly due to recent data showing a slowdown for head lice products in the US compared with strong growth in previous years.
For the six months to 30 June, operating expenses were steady at US$3.8 million (2015: US$3.7 million), while the net loss was around the same as last year at US$1.5mln.
Cash and equivalents were US$2.1 million, compared to US$4mln as at the end of 2015.