Safety and efficacy of hydroxy analogue of methionine and its calcium salt (ADRY+®) for all animal species

feed additive, hydroxy analogue of methionine, HMTBa, hydroxy analogue of methionine calcium salt, HMTBa-Ca, safety, efficacy
First published in the EFSA Journal
20 mars 2018
20 février 2018
Scientific Opinion


The European Commission asked EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) to deliver a scientific opinion on the safety and efficacy of ADRY+®. ADRY+® consists of hydroxy analogue of methionine (HMTBa) and its calcium salt (HMTBa-Ca), both precursors of L-methionine. HMTBa and HMTBa-Ca are currently authorised for use as a nutritional additives, under the functional group ‘amino acids, their salts and analogues’. ADRY+® is produced by chemical synthesis and it is intended to be used in feed for all animal species and categories. The FEEDAP Panel concluded that ADRY+® is safe for the target animals. The use of the additive in animal nutrition is not expected to result in an accumulation of HMTBa or its metabolites in edible tissues and animal products. Therefore, its use does not raise safety concerns for the consumer. ADRY+® is irritant to eyes and not irritant to the skin. The FEEDAP Panel cannot conclude on the skin sensitisation potential of this additive. The exposure of the users to the additive by inhalation is expected to be low. The use of this product as a feed additive does not represent a risk to the environment. ADRY+® is an effective source of ethionine for protein synthesis in non-ruminant animals and fish, although HMTBa may show a lower bioefficacy than DL-methionine. In ruminants, HMTBa is more slowly degraded in the rumen than DL-methionine.

Panel members at the time of adoption

Gabriele Aquilina, Giovanna Azimonti, Vasileios Bampidis, Maria de Lourdes Bastos, Georges Bories, Andrew Chesson, Pier Sandro Cocconcelli, Gerhard Flachowsky, Jürgen Gropp, Boris Kolar, Maryline Kouba, Marta López-Alonso, Secundino López Puente, Alberto Mantovani, Baltasar Mayo, Fernando Ramos, Guido Rychen, Maria Saarela, Roberto Edoardo Villa, Robert John Wallace and Pieter Wester.
Panel on Additives and Products or Substances used in Animal Feed
feedap [at]
EFSA Journal 2018;16(3):5198
Question Number
On request from
European Commission