'insufficiently effective' is correct and usable in written English.
You could use it to describe something that is not as effective as it should be. For example, you could say: "The current regulations are insufficiently effective in curbing the rise in obesity."
Other potential medication errors might be due to medication that is not or insufficiently effective, or to inadequate monitoring of the effects of the therapy.
The risks of these substances being contaminated, or insufficiently effective, are considerable.
I don't just mean that it's poor value for money or insufficiently effective - it's much worse than that.
PAGE A23 PAUL KRUGMAN President Obama's pursuit of bipartisanship, and the cuts imposed by "centrists," have led to an inadequate, insufficiently effective stimulus bill.
It says: "As it currently operates and is constituted, it is insufficiently effective, largely unaccountable, opaque, and failing to reflect the radically changed media environment".
Speaking to Russian newspaper Izvestia in November, Ivan Nikitchuk - the Communist party MP who drafted the bill - said the 2013 anti-LGBT law was "insufficiently effective".
At present, the lack of highly effective therapeutic targets for TNBC leaves standard chemotherapy, for example use of combination of anthracycline and taxane, however these agents are insufficiently efficacious [21].
This was comprehensively rejected by the judge in his report as insufficiently independent or effective.
The intervention evaluated in the present study appeared both insufficiently feasible and effective for patients with GOA.
The results of the present study indicate that the proposed intervention for patients with GOA was insufficiently feasible and effective.
Key Findings and Conclusions In general, HIV/AIDS efforts which UNICEF has supported to date have been relevant, cogent, and effective, albeit insufficiently extensive or intensive.
