Two weeks after a treatment and nothing has changed? Every treatment runs on its own clock

I'm Dr. Chihak Lee, director of Miso Clinic in Daegu, Korea. This blog is where I retell the clinical columns from our website in plainer language. The Korean version of this post is here.

"It's been two weeks and nothing has changed."

That is the sentence I hear most often in my consulting room. And almost every time, I give the same answer: "It's not time to look yet."

Today I want to show you that this isn't me trying to calm anyone down. Different treatments really do run on different clocks, and the differences are measured in months, not days.

Every treatment has its own clock

Botulinum toxin is the fastest. Within two days you can see the frown lines soften when you actually frown. But here's the interesting part: the lines you see at rest take much longer. In one study, on day two about eight in ten people showed a change when frowning, but only half showed a change with a neutral face. That moment in front of the mirror when you think "it's the same" — it's actually in the data. The effect peaks at about a month, and the point where people feel most satisfied was two to three months. Two weeks is not the peak.

Fillers go the other way. The fullest moment is right after the injection; from there it settles down as swelling goes away. So if you love it immediately, it may actually be slightly too much. You'll often hear "it takes two weeks to settle." Honestly, no study has ever measured volume at two weeks. It's a habit, not a finding.

Radiofrequency lifting is on the slow side. In a study that followed twenty Korean women, at four weeks three dermatologists looking at photos could not say anything had changed. Yet at that same point, a device measuring skin elasticity already showed improvement. The inside of the skin changes first; the outside catches up later. It became visible at twelve weeks, and peaked at four to six months.

Collagen-stimulating treatments (what people call "boosters") are slower still. When researchers actually took small skin samples from people, they found no new collagen at two weeks, thin new collagen at around two months, and proper collagen only at three to four months. I used to say "collagen starts forming at four to six weeks" too. I couldn't find human evidence for that. It came from mouse studies.

Why the mirror misses the change

"I see myself every day, so I can't tell" has a basis too. Human eyes recalibrate within minutes of repeated exposure. On top of that, you see yourself as a mirror image, while your family and I see the real one. We are literally looking at different faces.

That's why we always take photos before a treatment. Same spot, same light, same angle. It's almost the only way to later answer "did anything really change?"

The single most surprising number

At 90 days after ultrasound lifting, doctors judged 92% of patients as improved — but only 42% of the patients themselves felt that way. At one year it flips: doctors saw remaining improvement in only 43%, while patient satisfaction was over 95%.

Early on, people feel "it didn't work." Later, they feel "it's still fine." Those two lines explain most of the misunderstandings in my clinic.

So this is what I tell people

For botulinum toxin, look at about a month, not two weeks. For radiofrequency and ultrasound, don't judge before three months. For fillers, becoming less puffy than day one is normal. And we don't add more just because it looks "not enough" — there's data showing that more product did not mean more satisfaction.

"Too early" and "didn't work" are different things. Every number and source behind that distinction is in the full column on our website.

👉 Full column: When results show — and when to judge (Korean; the site also has an English section)

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Chihak Lee, MD · Miso Clinic · 4F Bombom Bldg, 125 Dongdeok-ro, Jung-gu, Daegu 41940, Korea · www.clinicmiso.co.kr
General information only; individual decisions are made in consultation.