The Truth Behind Spanish Fly: Myths vs. Reality (2025)

Highlights

• People have used Spanish fly as an aphrodisiac since antiquity.

• Spanish fly often doubled as a convenient poison to eliminate rivals.

• No scientific evidence backs the efficacy of Spanish fly as a libido booster.

• The active ingredient in Spanish fly is a toxin that can cause organ failure and death.

• Among its many horrific effects and side effects, Spanish fly may cause long-lasting erections in some victims.

• Fortunately, products sold as Spanish fly contain only tiny amounts of cantharidin, the active substance in Spanish fly — or none at all.

• Unfortunately, these products also have no proven track record as libido boosters.

Not much about this famous traditional ”aphrodisiac” adds up. It’s not Spanish, it doesn’t come from a fly, and it doesn’t boost your sexual prowess. If you rely on Spanish fly to up your sexual performance, you’re more likely to poison yourself than to boost your libido. Traditionally, Spanish fly was a “love potion” made of dried and ground blister beetles. People have attributed aphrodisiac effects to it since ancient Roman times, when emperors and empresses used it to arouse or kill others. Some well-known historical figures who are thought to have ruined their reputations and the lives of others with Spanish fly were Roman Emperor Augustus Caesar’s wife, Livia; Louis XIV of France; and the Marquis de Sade. The latter allegedly poisoned several prostitutes and was forced to flee to Italy as a result. A more recent “proponent” of Spanish fly (though he may have been joking, of course) was comedian Bill Crosby, who was later convicted of sexual assault and released from jail after his conviction was overturned. “. . . and the girl would drink it, and . . . Hello America!” – Bill Crosby on Spanish fly The myths about the aphrodisiac properties of Spanish fly stem from ancient times. Back then, people didn’t understand how the toxins in ground blister beetles work, and they were quick to attribute aphrodisiac properties to some of their side effects.

What Is Spanish Fly?

Spanish fly consists of ground blister beetles (Lytta vesicatoria). Male blister beetles secrete the substance and “hand” it to females as a mating gift. The females cover their eggs in it to protect them from predators.Called cantharidin, the active compound in this concoction is highly toxic. When someone or something swallows it, cantharidin damages mucous membranes, potentially causing some organs to fail.It takes only 10-65 milligrams of cantharidin to kill a person. As little as 1 milligram per kilogram of body weight can be fatal. A paper published in 1954 included a case study of a fisherman who used blister beetle extract as bait. The man pricked his finger after he handled the toxin. He then sucked the wound and ingested a lethal dose of cantharidin.Traditional Spanish fly preparations likely consisted of ground beetles mixed into foods and drinks. Often, the person who consumed the concoction wasn’t aware of the trickery.In addition to treacherous royalty, gladiators may have used Spanish fly for orgies. Today, some communities may use Spanish fly concoctions to encourage their animals to mate.Surprisingly, there is a legitimate medical use for cantharidin, though it’s never taken orally. Because of its destructive effect on skin cells, it’s used to treat the skin condition molluscum contagiosum. However, even in that case, it can only be applied by a healthcare provider.It’s also used off-label (meaning without FDA approval) to treat warts.

Spanish Fly as an Aphrodisiac

Cantharidin may have worked as a sexual pleasure-enhancing compound by causing blistering and inflammation and boosting blood supply in the urinary tract. In some people, burning sensations in the urinary tract may cause sexual arousal-like responses. Having sex is a scratch-an-itch type of reaction to these sensations. Cantharidin causes sexual arousal through tissue damage and inflammation. It does not boost testosterone levels or libido or widen blood vessels like ED medications such asViagra.

Spanish Fly Myths

People of antiquity and the Middle Ages didn’t understand how cantharidin worked. They saw sexual arousal in some cases and assumed that Spanish fly was an aphrodisiac. Over centuries of observations and scientific ignorance, the myths about cantharidin’s effects grew and spread. Many persist to this day.

Myth 1: Spanish Fly is a Safe and Natural Remedy for Sexual Dysfunction

Spanish fly may be natural, but it certainly isn’t safe! Cantharidin is a poison. If you take enough of it, sexual dysfunction will be the least of your worries. Even a tiny amount of Spanish fly can lead to an overdose and death.

Myth 2: Spanish Fly Works by Stimulating Sexual Arousal

Cantharidin may induce a toxic shock to which your body may respond by boosting blood flow to flush the toxin out of your system. This can lead to or enhance an erection, but the substance does not boost testosterone levels or libido.

Myth 3: Spanish Fly Has Been Used Successfully for Centuries Without Issues

The validity of that statement depends on your definition of success. For someone who wanted to murder a rival in ancient times and did so by cantharidin, Spanish fly may have been successful. For boosting sexual prowess, however, it was probably an abject failure. Cantharidin taken orally could only have functioned successfully as a deadly poison.

Myth 4: Spanish Fly is Legal and Approved for Use as a Sexual Enhancement Product

The FDA stance on Spanish fly is clear: The Administration has not approved any products that contain cantharidin for sexual enhancement. The only FDA-approved, cantharidin-based product is Ycanth for the treatment of molluscum contagiosum.Spanish fly legality is a sensitive question in the U.S. The FDA has included cantharidin as a nominee on its Bulk Substances List, meaning that it can be used as an ingredient in compound medications to treat conditions that can’t be treated with other medications. However, the recommendation is that use of the substance be limited to use as a topical solution in professional office settings.Selling non-prescription cantharidin-containing products is illegal in the U.S. and many other countries.

The Reality of Spanish Fly

Spanish fly is more of a legend than a practical solution for sexual dysfunction. We know that what people believe to be an aphrodisiac is a potent poison, and we can’t point to scientific evidence supporting its efficacy as a libido booster.Most Spanish fly effects and side effects are dangerous and potentially deadly. These can include:

• Bleeding of the upper gastrointestinal tract
• Kidney damage and failure
• Abdominal pain
• Rectal bleeding
• Vaginal bleeding
• Urinary tract damage
• Painful, long-lasting erections
• Bloody urine

Spanish fly’s history is rife with accounts of poisonings and deaths to this day. It is banned as an aphrodisiac in many countries, and with good reason — there is no antidote for cantharidin poisoning.

Spanish Fly: The Bottom Line

Spanish fly is a dangerous myth wrapped around a real and even more dangerous poison. Bugs won’t eat it — and neither should you.

Erection-Boosting Alternatives to Spanish Fly

Peddlers of dubious libido-boosting supplements have always sought to cash in on the myth and hype value of the Spanish fly name. The products they sell as Spanish fly contain negligible amounts of cantharidin, or none at all.Still, you assume a risk when you consume these products. What if someone spikes your unregulated supplement with a lethal dose of poison to ensure it lives up to its name? This is not as implausible as it might sound — Cantharidin-based supplements are still available in some regions of the world, and it’s not a stretch to think that some might find their way to the U.S.There’s also the danger that this potentially lethal ingredient could be added to sexual enhancement products but not disclosed on the label. Because the FDA doesn’t regulate over-the-counter supplements, undisclosed ingredients in over-the-counter supplements is a common finding.For this reason, the FDA maintains a list of Tainted Sexual Enhancement and Energy Products that contain hidden ingredients and continually adds new products to the list.Instead of trusting your sexual health to unregulated peddlers of myths and high tales, go for FDA-approved solutions. We carry medications that are proven to treat erectile dysfunction, like Viagra and Cialis along with the generic medications sildenafil, vardenafil, and tadalafil.Clean up your diet and lifestyle, work out, limit alcohol, and quit smoking. Treat the underlying health conditions responsible for your ED.Most importantly, never make a significant healthcare decision without consulting a doctor. Only qualified healthcare providers can give you scientifically backed guidance and effective solutions.

Trust eDrugstore for Safe Solutions That Work

There’s nothing mythical or magical about ED treatment. At eDrugstore, we carry safe, science-backed solutions that work. Discuss available treatment options with your doctor.We carry several FDA-approved ED drugs and their more-affordable generic equivalents. To provide you with the prescription you need and an optimal treatment approach, we offer a complimentary consultation with a U.S.-licensed doctor.Place our order now and make erectile dysfunction a thing of the past. Shipping is always free, and we deliver quickly and discreetly. Disclaimer: This article provides general information about health and related topics but is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.