Zeno was a Greek physician.

He was one of the most eminent of the followers of Herophilus, whom Galen

Galen

Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...

 calls "no ordinary man," and who is said by Diogenes Laërtius

Diogenes Laertius

Diogenes Laertius was a biographer of the Greek philosophers. Nothing is known about his life, but his surviving Lives and Opinions of Eminent Philosophers is one of the principal surviving sources for the history of Greek philosophy.-Life:Nothing is definitively known about his life...

 to have been better able to think than to write. He lived probably at the end of the 3rd and beginning of the 2nd centuries BC, as he was a contemporary of Apollonius Empiricus

Apollonius (physician)

Apollonius was the name of several physicians in the time of Ancient Greece and Rome:*Apollonius Antiochenus, , was the name of two physicians, father and son, who were born at Antioch, and belonged to the Empiric school. They lived after Serapion of Alexandria, and before Menodotus, and therefore...

, with whom he carried on a controversy concerning the meaning of certain marks that are found at the end of some of the chapters of the third book of the Epidemics of Hippocrates

Hippocrates

Hippocrates of Cos or Hippokrates of Kos was an ancient Greek physician of the Age of Pericles , and is considered one of the most outstanding figures in the history of medicine...

. He gave particular attention to the materia medica

Materia medica

Materia medica is a Latin medical term for the body of collected knowledge about the therapeutic properties of any substance used for healing . The term 'materia medica' derived from the title of a work by the Ancient Greek physician Pedanius Dioscorides in the 1st century AD, De materia medica libre...

, and is perhaps the physician whose medical formulae are quoted by Galen, in which case he must have been a native of Laodicea

Laodicea

- Turkey :*Laodicea on the Lycus, in Phrygia*Laodicea Pontica, in the Pontus*Laodicea Combusta, in Pisidia- Other countries :* Laodicea , in Greece* Laodicea , in Iraq* Laodicea in Media, former name of Nahavand, Iran...

. He is mentioned in several other passages by Galen, and also by Erotianus

Erotianus

Erotianus was the author of a Greek work still extant, entitled Collection of Hippocratic words . It is uncertain whether he was himself a physician, and try to solve father of medicine Hippocrates or merely a grammarian, but he appears to have written some other works on Hippocrates besides...

; perhaps also by Pliny

Pliny the Elder

Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

, Caelius Aurelianus

Caelius Aurelianus

Caelius Aurelianus of Sicca in Numidia was a Roman physician and writer on medical topics. He is best known for his translation from Greek to Latin of a work by Soranus of Ephesus, On Acute and Chronic Diseases. He probably flourished in the 5th century, although some place him two or even three...

, Alexander of Aphrodisias

Alexander of Aphrodisias

Alexander of Aphrodisias was a Peripatetic philosopher and the most celebrated of the Ancient Greek commentators on the writings of Aristotle. He was a native of Aphrodisias in Caria, and lived and taught in Athens at the beginning of the 3rd century, where he held a position as head of the...

, and Rufus of Ephesus

Rufus of Ephesus

Rufus of Ephesus was an ancient Greek physician and author who wrote treatises on dietetics, pathology, anatomy, and patient care. He was to some extent a follower of Hippocrates, although he at times criticized or departed from that author's teachings...

, but this is uncertain.