Regimen vs. Regiment – What’s the Difference?

When your doctor prescribes you medicine to be taken according to a set schedule, are you on a regimen or regiment?

The difference in meaning between these two words is stark: one of them would prescribe a treatment routine, while the other might put you in a war zone. Clearly, spelling is important here.

To avoid ending up on the front lines of a dangerous battle, you will need to know the difference between these words. They are both nouns, and the only clue to their difference is the letter T at the end of regiment. They even have similar etymologies; both words can be traced back to the same Latin root verb.

Continue reading for a thorough explanation of these confusing words.

What is the Difference Between Regimen and Regiment?

In this post, I will compare regiment vs. regimen. I will use each of these words in at least one example sentence, so you can see them in context. Plus, I will show you a mnemonic device that will make choosing regiment or regimen much easier.

When to Use Regimen

regimen versus regiment What does regimen mean? Regimen is a noun. A regimen is a routine, or a prescribed course of medical treatment.

A physician might prescribe a regimen of three doses of medication per day. A personal trainer might also design an exercise regimen to promote healthy weight loss.

Here are a few more examples,

  • Sylvia’s exercise regimen includes squats, push-ups, lunges, and bicycle kicks four times per week.
  • Archibald’s doctor prescribed a strict regimen of antidepressants to help him improve his social functioning.
  • The shorter regimen also costs far less: under $1,000 per patient in developing countries, compared with as much as $3,000 for the current treatment, the WHO said. –The Wall Street Journal

Regimen is a singular noun. The plural form of this word is regimens.

Regimen is a direct importation from Latin, where it used to mean rule or government.

When to Use Regiment

definition of regiment definition of regimenWhat does regiment mean? Regiment is also a noun. A regiment is a permanent military unit or a general word for a powerful governing body.

The United States Army organizes its forces according to regiment. Regiments are further organized into battalions, brigades, and divisions, and other units.

These sentences use regiment in its proper context.

  • The small Iowa farm town was proud to have one of its own assigned to the 1st Air Defense Artillery Regiment.
  • The affiliation system currently in use by the US Army is designed so that the benefits of a traditional regiment system are not lost.
  • From 2005 to 2008, he served as the Marine Corps’ exchange officer to the Army’s elite 75th Ranger Regiment with headquarters at Fort Benning, Ga., deploying to Iraq and Afghanistan multiple times. –The Washington Post

When regiment is plural, it becomes regiments.

Regiment also originally came from Latin, but English borrowed it from French, where it was first used to describe a military unit.

Trick to Remember the Difference

define regimen define regimentRegimen and regiment only have one letter’s difference between them, but they mean very different things.

Regimen vs. Regiment Check: Since regiment and military each contain the letter T, it should be easy to remember that regiment refers to the organization of military units.


Is it regimen or regiment? Regimen and regiment are both nouns.

  • A regimen is a prescribed treatment schedule or an exercise routine.
  • A regiment is a unit of troop organization in the military.

Despite their similarity in spelling, they cannot be substituted for each other in any contexts.