Horu Horu no Mi

The Horu Horu no Mi is a Paramecia type Devil Fruit that grants the user the ability to create and control special hormones that can affect anyone they strike by however the user desires. Horu is short for "horumon" (ホルモン, hormone). It was eaten by Emporio Ivankov.

Strengths and Weaknesses
The major strength of the fruit, as demonstrated by Iva, is to create and manipulate special hormones. These hormones can manipulate various aspects of a person. These range from gender, body temperature, pigmentation, growth, and even emotional state. By turning their fore fingers into syringes and stabbing a person, the user is able to inject these hormones and change the person on a genetic level to whatever the user desires. This process can also be used by the user on themselves to aid them.

The fruit so far doesn't seem to have any specific weaknesses outside the standard Devil Fruit weaknesses.

Usage
The fruit's bestowed powers, as used by Iva, have been used for a variety of reasons. Typically, whenever he uses his power, he mainly changes the "gender", allowing him to either inject female hormones into a man to turn him into a woman or vice versa.

The fruit's powers are the source of Ivankov's "miraculous" powers, which, aside from gender changing, allow other miracles such as extreme healing, using them to allow for a body to adjust from a fatal-condition to having a chance of survival. However, while he can make the adjustment within the body to heal from these conditions, the miracle is also dependent on the person hit by the altering hormones, whereas only those with a strong enough will can survive and use their survival instincts via the hormones to their advantage. Depending on what the conditions the patient is in, as well as the hormones used, the receiver may suffer a shortening of lifespan in exchange for a "cure".

The named techniques that are used by Emporio Ivankov that involve the Devil Fruit are as follows:


 * Emporio Onna Hormone (エンポリオ・女ホルモン -Emporio Female Hormone-) : By injecting a male with special female hormones, Iva is able to transform them completely into a female. This was first seen being used on an inmate in Level 5.5. He can also use this on himself, doing so when he fights Sadi-chan. In addition, Iva was able to transform himself and other women (supposedly) into men, but this usage for his ability is not a named technique.
 * Emporio Chiyu Hormone (エンポリオ・治癒ホルモン -Emporio Healing Hormone-): By injecting special hormones meant to release the body's immune system's full potential into a sick person, Iva is able to cure them. This is the secret to his "miracle" healing. Since the hormones only unleash the immune system's potential, the chance of survival is mostly based upon the individual's will to live. In order to use this technique, 10 years of the target's life-span must be sacrificed in order to compensate for the energy used to heal the damage. This was first seen being used on Luffy to counteract Magellan's poison.

He has shown to make his head grow to the size of a giant.
 * Emporio Tension Hormone (エンポリオ・テンションホルモン): By injecting special adrenaline affecting hormones, Ivankov can provide a tired person with a supply of adrenaline that can relieve tension and allow for easier movement for an entire day. There is an aftereffect 24 hours after being injected with this hormone, which has yet to be revealed since the time-skip from traveling from Impel Down. This was first seen being used on an exhausted Luffy.
 * Emporio Gan Men Seichō Hormone (エンポリオ・顔面成長ホルモン -Emporio Face Grow Hormone-): By injecting special face manipulating hormones, Ivankov can make a person's face expand to enormous proportions. This was first seen used by Ivankov on himself during the escape from Impel Down level 4 to make his Death Wink technique into a more powerful version called Hell Wink.

Trivia

 * In a SBS, a fan asked Oda if he would draw the Straw Hats as they would if they were genderswaped by Iva's hormones. In response, Oda provided the following drawings. For the male crewmembers turned female, they would use a typical Japanese feminine style of talking. The opposite is also said for the female crew members with them using a typical Japanese musculine style of talking. Female Luffy is apparently a vegetarian. Female Zoro apparently doesn't like putting a sword in her mouth as it would chip her teeth. Female Sanji's specialty would be sweets. For most of the Straw Hats, the genderswap is very apparent. Brook however isn't so apparent since he has no flesh to help identify whether he was injected with Iva's gender changing hormones or not.