First: The word “collagen” originates from Greek and consists of two parts: “kolla,” meaning glue, and “gen,” meaning producer. Here, it refers to the protein component.

Scientifically, collagen is the main protein in connective tissues (tissue in the human body is an intermediate stage between a single cell and a complete organ, and tissue consists of similar cells that combine to form a type of tissue. In the human body, there are four types of tissues: connective, muscular, nervous, and epithelial). It is found in muscles, skin, ligaments, cartilage, bones, and tissues, constituting up to 25% of the total proteins in mammals and some other creatures.

Collagen tissues can be hard (bones), soft (tendons), or a gradient from hard to soft (cartilage). Collagen is also abundant in the cornea, blood vessels, intestines, intervertebral discs, and tooth dentin.

Collagen is used in many treatments, including cosmetic surgery, fracture repair, dermatological diseases, wound healing, tissue regeneration, and joint treatment.

Second: Regarding collagen derived from fish, it is generally considered permissible since fish are ḥalāl and do not require slaughter. The Prophet (peace be upon him) said, “Its water is pure and its dead are lawful, [referring to the sea].” The exception would be fish that are disputed in terms of permissibility, such as shark.

For collagen derived from ḥalāl animals like properly slaughtered cows and sheep, it is permissible whether it has undergone a transformation process (᾽istiḥālah) or not.

For collagen derived from inherently forbidden animals like pigs, or forbidden due to circumstances like carrion, the ruling is as follows:

• If collagen is used in its original form without processing (hypothetically), it is not permissible except in cases of necessity, similar to other forbidden treatments that are only allowed in cases of necessity or widespread need that approximates necessity.
• If it has been processed to the point of transformation (᾽istiḥālah), this type of collagen is permissible according to the Ḥanafī and Mālikī schools, and one opinion among the Ḥanbalīs. This is because the transformation process has turned it into a different substance, much like how burned pig transforms into ash in the ground or how wine turns into vinegar.

The transformation process, whether natural or through treatment, removes the forbidden characteristics of the original substance.

Therefore, all collagen products sold in the form of medicine, such as tablets, capsules, and liquids, that have undergone processing and transformation cannot revert to their original state. Even if derived from forbidden animals like pigs or carrion, they are permissible in their new form.

Fatwā issued by Dr. Khālid Naṣr