Charles Benbrook is chief scientist of the Organic Center in Oregon, wrote a much-quoted paper claiming that transgenic crops increase pesticide use.
Food and Water Watch
Food and Water Watch is an NGO interested in a range of topics including not only GMOs but irradiation and nanotechnology. Recent campaigns include activism on AquaBounty's transgenic salmon.
Greenpeace
Greenpeace has released several popular-level reports critical of transgenics.
John Losey
John Losey has researched the potential for monarch butterfly caterpillars to be harmed by transgenic Bt-expressing pollen.
David Suzuki
David Suzuki was a respected scientist and science communicator until his retirement in 2001. He has made public statements against GM foods.
Nassim Taleb
Nassim Taleb is an economist interested in the Precautionary Principle.
Consumers Union is the publisher of Consumer Reports magazine, which has recently come out as anti-GM.
Z El-Shamei
Z El-Shamei wrote a paper describing minor cellular-level differences in rats fed GM feed.
ENSSER (European Network of Scientists for Social and Environmental Responsibility)
ENSSER is best known for their statement on a lack of scientific consensus for GM safety.
Environmental Working Group
Environmental Working Group is most famous for their annual “Dirty Dozen” report on pesticide residues, but they also have multiple other consumer reports.
Vani Hari (Food Babe)
Vani Hari has a popular blog questioning the safety of GM products and many other standard food practices.
Don Huber
Don Huber claimed to have isolated a new pathogen associated with glyphosate.
Manuela Malatesta claimed to have found cellular-level differences in mice fed GE soy.
Joseph Mercola
Joseph Mercola is an alternative-medicine web entrepreneur.
Belin Mezzomo
Belin Mezzomo was popularly portrayed as having shown that Bt toxin causes leukemia.
Mehmet Oz (Dr. Oz)
Mehmet Oz is a surgeon and TV doctor who is outspoken about GMOs as well as many alternative therapies.
Arpad Pusztai
Arpad Pusztai was portrayed as having shown that GE potatoes have mysterious harmful effects not linked to the proteins they produce.
Stephanie Seneff
Stephanie Seneff blames glyphosate for “most of the diseases and conditions associated with a Western diet.”
Gilles-Eric Seralini (Séralini)
Gilles-Eric Seralini has written many anti-GM papers. His most famous one involved photographing rats with huge tumors.
Jeffrey Smith (Institute for Responsible Technology)
Jeffrey Smith is most famous for “Seeds of Deception” and “Genetic Roulette”.
Sándor Spisák
Sándor Spisák did not actually study transgenics, but has been used by anti-GMO activists because he is believed to have found that DNA from our food can wind up in our bloodstream.
Bill Freese of the Center for Food Safety, wrote a paper on regulation of transgenics.
GMWatch
GMWatch is an organization that publishes many anti-GM works and promotes conspiratorial origins for pro-GM organizations.
Michael Pollan
Michael Pollan is a food writer famous for “The Omnivore's Dilemma”, “Botany of Desire”, “In Defense of Food”, “Food Rules”, and other works; advocates policy changes.
Vandana Shiva
Vandana Shiva an eco-feminist and public figure who is interested in “Terminator genes” and Indian farmer suicides.
Mae-Wan Ho (Institute of Science in Society, ISIS) is most famous for the “800+ scientists against GMOs” letter, but has written several other anti-GM pieces.
Organic Consumers Association
Organic Consumers Association (Millions against Monsanto, Ronnie Cummins) is best known for their project Millions against Monsanto, but have many other campaigns.
Henry Rowlands (Sustainable Pulse, GMO Evidence, GMO Seralini, GMO Carman, Global GMO Free Coalition, GM Watch)
Henry Rowlands is primarily known for running anti-GM websites.
Thierry Vrain
Thierry Vrain is a retired plant and animal scientist, known for his TED talk about GMOs.
Prominent GMO Advocates
Environmental Claims
Jian Duan
Jian Duan is a USDA entomologist who performed a meta-analysis of transgenic Bt's effects on honeybees.
Health Claims
Chelsea Snell
Chelsea Snell has a review focused only on GMO feeding trials that were multigenerational and/or long-term.
Alison van Eenennaam
Alison van Eenennaam reviewed scientific literature on the effect of GMOs on livestock health, dating from the introduction of GMOs.