Background: The unrefined nature of the herbal preparations from Vernonia amygdalina (VA) and toxicity potentials of Sniper may both have severe consequences on the biochemical and genetic systems.

Objectives: To assess the microscopic and macroscopic effects of these substances.

Methods: VA leafs and Sniper were prepared and dissolved in distilled water to give different concentrations. Series of baseline tests were carried out to establish concentration range for root growth. Series of twelve onion bulbs of three per series was prepared, with a series of three onion bulbs serving as control. Chromosomal aberrations were statistically analysed using chisquared test. Root bundle mean length was obtained after 96 hours and EC₅₀ values at 95% confidence interval was determined from a plot of root length against sample concentrations using Microsoft Excel software.

Results: Total cytotoxic effect was induced by 2% sniper and 70% VA. EC₅₀ for VA and sniper were 33.07 and 0.346 respectively. The two substances induced chromosomal aberrations and the effect was concentration dependent.

Conclusion: There are risks of these widely used substances for therapeutic and environmental purposes.