How a False Medical Claim Turned the Tokay Gecko Into a Trafficking Target

The Tokay gecko does not hide. At up to 35 centimetres long and coloured a vivid blue-grey spotted with orange-red, Gekko gecko is built to be noticed. Its call, a loud, two-syllable bark that sounds like its own name, carries across rooftops and through walls on humid nights across South and Southeast Asia, including parts of Northeast India. It clings to vertical surfaces using millions of microscopic hair-like structures called setae on its toe pads, generating van der Waals forces strong enough to hold its body weight many times over. It is one of the largest gecko species on earth, and in the ecosystems it inhabits, it is a useful one: a predator of insects, smaller lizards, and the occasional small rodent.

None of that is why it is being caught by the hundreds of thousands.





Somewhere in the early 2000s, a rumour circulated through parts of Southeast Asia and then further afield: that Tokay gecko, dried, powdered, or consumed whole in alcohol, could treat HIV and AIDS. The claim had no clinical basis. No peer-reviewed study has demonstrated any antiretroviral activity in Gekko gecko tissue. No pharmacological mechanism has been identified. The World Health Organisation has not recognised any gecko-derived compound as a treatment for any condition. The rumour was not a misreading of a study. It was a rumour.


A secondary claim followed: that the gecko could treat diabetes, cancer, and asthma. These, too, have no evidentiary foundation in controlled research. Traditional medicine systems in parts of China and Southeast Asia have historically used gecko preparations, but traditional use is not clinical evidence of efficacy, and the scale of demand now has no precedent in any historical practice.

TRAFFIC, the wildlife trade monitoring network, documented Tokay gecko seizures running into the hundreds of thousands of individuals across multiple countries. The Philippines, Indonesia, and parts of Thailand became major source countries. Traders advertised geckos by weight, heavier specimens commanded higher prices, on the belief that larger animals contained more of the supposed active compound. There is no evidence that body mass correlates with any therapeutic effect, because no therapeutic effect has been established. The price premium on large animals simply accelerated the removal of reproductively mature adults from wild populations.

In India, the Tokay gecko is listed under Schedule IV of the Wildlife Protection Act, 1972, making its capture, trade, and possession without authorisation a criminal offence. Enforcement agencies in Assam, Meghalaya, and other northeastern states have recorded seizures, though the full scale of domestic trade is difficult to quantify. Internationally, Gekko gecko was added to Appendix II of CITES in 2013, requiring that any commercial export be accompanied by documentation that the trade is not detrimental to wild populations.



Tokay geckos are territorial and slow to reproduce relative to the pace at which they are being removed. A female typically lays one or two hard-shelled eggs per clutch, gluing them to a surface where they incubate for several months. They do not produce the large, fast-reproducing broods that allow some species to absorb heavy collection pressure. Population data for wild Tokay geckos is incomplete, which itself is a problem: it makes it harder to set defensible harvest limits and easier for traders to claim populations are stable.

The ecological role of the species compounds the concern. Tokay geckos are significant insect predators in the habitats they occupy. Removing them at scale shifts the balance of the prey communities they regulate. The downstream effects on agricultural pest pressure and disease-vector insect populations have not been systematically studied, but the direction of the effect is not difficult to predict.

The Tokay gecko trade illustrates something that conservationists encounter repeatedly: once a species acquires a high-value medical reputation, factual correction travels more slowly than the economic incentive. A trader does not need to believe the claim is true. They need to believe a buyer believes it. As long as demand exists, and it has persisted for two decades, the supply chain reorganises around enforcement pressure rather than collapsing under it.

The species that survive this pattern are usually the ones that become economically worthless before their populations collapse, or the ones where enforcement becomes consistent and costly enough to change the risk calculation for traders. Neither has fully happened yet for the Tokay gecko. What has happened is that a lizard with no demonstrated medical value, living perfectly well on the walls of homes across Asia, became one of the more heavily trafficked reptiles on the planet because a claim with no evidence spread to people with enough money to act on it.