Ask a Korean student or twenty-something what the fastest way to make real money is, and within a couple of answers the same word always comes up: bioequivalence.
The gig where you lie in a hospital for a few days and supposedly walk out with ₩2 million. Korean forums have called it by a scary nickname for over twenty years — the “maruta” job, after the old wartime slang for a human test subject. What does it actually involve? Does it really pay that well? And why can’t foreigners do it? Here’s the whole thing, in numbers.
The short answer
- A bioequivalence trial pays ₩350,000 to ₩2.5 million after tax — set by how many nights you stay in the hospital.
- After one trial, you can't do another for 6 months. That's why it can never become a "job."
- Foreigners can't realistically join — three walls: language, identity checks, and visa.
What exactly is a bioequivalence trial job?
It’s a test to confirm that a generic copy of an off-patent drug gets absorbed by the body exactly like the original. To sell a generic, a drugmaker has to prove “ours absorbs just as well as the brand-name version” — and that proof ultimately has to come from real human bodies. So they recruit healthy adults, dose them with both drugs a set time apart, and draw blood to compare the concentration curves.
Here’s the key thing to understand: this is not a brand-new substance being put into a human for the first time ever. The subject is an ingredient from a drug that has already been sold for decades. The “maruta” nickname stuck because of how it sounds — not because of what the trial actually is.
Applying doesn’t mean you’ll get in
This is the part people get most wrong. It isn’t an “anyone can do it” gig — it’s a gig you have to pass a medical screening for.
What gets you filtered out at screening:
- Smokers — effectively the most common reason for rejection
- High or low blood pressure
- Underlying conditions: fatty liver, herniated disc, arthritis, asthma, pneumothorax, atopic dermatitis
- Taking any regular medication
- BMI below 18 or above 30
Why so strict?
Because the test is about comparing how fast a drug is absorbed. Too many variables in a participant's body and the data loses all meaning. Smoking, drinking, underlying illness, and medication all affect absorption. Some of it is about protecting participants — but fundamentally, the rules exist to protect the data.
Which is why a fair number of people show up for the screening (blood draw, ECG, urine test) and get turned away. The screening is usually unpaid, or pays only a small travel allowance.
So what do you actually do for all those days?
Every trial has a different schedule, but it roughly looks like this.
📋 Rough payout by length of trial
| Format | Hospital stay | Rough payout |
|---|---|---|
| Short, two admissions | 1 night, 2 days × 2 | ₩350K–600K |
| Standard | 2 nights, 3 days × 2–4 | ₩700K–1.2M |
| Mid-length, continuous | 6–7 days straight | ₩1.2M–1.8M |
| Long, continuous | 12 nights, 13 days | ₩2M–2.5M |
A day goes roughly like this. You’re admitted the evening before and fast overnight, then take the drug in the morning. After that comes the real work. For the first 1–2 hours after dosing, they draw blood every 15–20 minutes. You sit in bed with a line in your arm, and the intervals slowly stretch out — 24 hours, then 48 hours later.
The time between draws is all waiting. You sit in a hospital bed with your phone, watch Netflix, or sleep. The word people who’ve done it keep using isn’t “hard” — it’s “boring.”
How Koreans actually prep
- Power bank and earbuds — whether your bed is near an outlet is a coin flip
- Fasting is long. Planning "what we'll eat when this is over" has basically become a ritual among participants
- The blood-draw marks on your arm linger for days. If you were planning on short sleeves, keep that in mind
So is it a good gig once you do the hourly math?
Here’s where it gets interesting. South Korea’s 2026 minimum wage is ₩10,320 an hour. If you got ₩2.5 million for a 12-night, 13-day trial, and you count all 24 hours of those 13 days as time on the clock, that works out to just over ₩8,000 an hour — below minimum wage.
Worth knowing about the tax side, too. The money is treated as miscellaneous income, not wages. You’re not enrolled in the four major social insurances, the amount you’re quoted is usually already after tax, and you can claw some of it back when you file your comprehensive income tax the following May.
Beyond bioequivalence: Korea’s other legendary high-pay gigs
These are the ones Korean forums bring up every single year under the banner of “big money, short time.” Most share one thing — you work hours or in conditions nobody else wants.
Can foreigners do it?
The honest answer
Bioequivalence trial gigs are effectively off-limits, for three reasons.
- Language — the informed-consent process (IRB rules) requires proving the participant fully understands the risks, and every document and explanation is in Korean.
- Identity verification — the check on the six-month re-participation ban runs on the resident-registration-number system.
- Visa — on a tourist visa (B-2) or visa-free entry, any form of paid activity is illegal. Even student (D-2) visa holders need separate permission for part-time work, and this kind of work isn't covered by it.
Foreigners with valid residency in Korea actually do a different set of short gigs: film and drama extras (there’s steady demand for foreign faces), native-speaking conversation partners, tourist interpretation assistants, and brand-event models. But even these hinge on your visa, so always check your own status of residence first.
What this story is really about
Bioequivalence gigs have circulated on Korean forums for twenty years not just because of the money. It’s the fact that an option exists — rent out your body for a few days and walk away with a lump sum — that has hardened into a kind of symbol for twenty-somethings who suddenly need tuition or a housing deposit.
As a traveler, this is a story you’ll never take part in. But few subjects compress the way Korea’s twenty-somethings do their mental arithmetic — what they’re willing to trade instead of pinching pennies on coffee — quite like this one.
Sources
- Namu Wiki — bioequivalence test part-time jobs (payout tiers, entry requirements, blood-draw intervals)
- MediCleo — what trial participants receive (payment method, miscellaneous-income treatment, no social insurance enrollment)
- Ministry of Employment and Labor — 2026 minimum hourly wage of 10,320 won
- Sisa Journal — clinical trial 'maruta job' false accusation (the nickname's origin vs. reality)