Honestly, I Didn't Know About These Side Effects 3 Years Ago

Honestly, I Didn't Know About These Side Effects 3 Years Ago

Please Read This Before Your Procedure


Q. I've heard Secret RF is safe because it delivers Radiofrequency (RF) energy through needles — does it really have side effects?

A. It does. The three most common ones are erythema, hyperpigmentation, and micro-scarring. In most cases, these aren't caused by the device itself — they come down to energy level and depth settings.


Q. Does skin type play a role?

A. Yes. Fitzpatrick skin types 3–4, which are especially common among Korean patients, carry a significantly higher risk of PIH (post-inflammatory hyperpigmentation).

What Makes This Procedure Different

Secret RF works by inserting microneedles into the skin

and delivering Radiofrequency (RF) energy directly from the needle tips,

creating precise thermal stimulation within the Dermis.

Unlike Fraxel or Laser toning,

Secret RF uses electrical energy rather than light.

That means it's less affected by melanin absorption,

and is theoretically considered lower-risk for hyperpigmentation.

But here's the important caveat.

"Theoretically lower risk" is not the same as

"zero risk."

Why Does Erythema Last Longer for Some Patients?

"Erythema and hyperpigmentation after Secret RF? Here's what I've observed about the three most common side effects of RF procedures — and how to avoid them."

— Dr. Wi Young-jin (Seoul Beautystone Clinic)

Last month, a patient came in who had received three Secret RF sessions at another clinic

and had been dealing with persistent erythema on both cheeks for two months.

She was in her late 30s and had a mild pre-existing tendency toward facial redness.

When I reviewed her treatment records, the energy levels were quite aggressive.

A depth of 3.5mm at level 5 or above,

applied at full intensity across the entire face.

Here's where it gets nuanced.

Secret RF needle depth can be adjusted from 0.5mm to 3.5mm.

The deeper range (2.5–3.5mm) targets Collagen remodeling,

while the shallower range (0.5–1.5mm) addresses Pores and Fine Lines.

When you apply full depth and full intensity

to skin that already has a tendency toward redness,

the cumulative thermal load on the capillaries builds up.

That's what leads to chronic, persistent erythema.

The second most common issue is PIH —

post-inflammatory hyperpigmentation.

While Secret RF carries a lower hyperpigmentation risk than light-based procedures,

inadequate sun protection after the procedure

can cause the thermally stimulated areas to darken significantly.

Based on my own data,

among patients who received Secret RF over the past year,

the rate of PIH was approximately 3–4%.

The majority of those cases involved patients

who had spent time at the beach or outdoors within two weeks of their procedure.

The third concern is micro-scarring —

small, dot-like marks at the needle insertion points.

To be direct about this:

this one has more to do with the practitioner than the device.

Overlapping passes on the same area,

or applying excessive needle pressure,

can leave residual track marks on the skin.

How I Approach This in My Clinic

Settings need to be customized based on your skin type and primary concern.

In most cases, I take one of two approaches —

though occasionally a third scenario applies.

One of the most common misconceptions I encounter is this:

"Higher energy means better results" — and that's only half true.

Push beyond what your skin can tolerate,

and you cross the line from results into side effects.

The Three Questions I Hear Most Often in the Clinic

Q1. It's been a few days since my Secret RF procedure and my cheeks are still red. Should I be worried?

A. Erythema in the first 3–5 days after a procedure is a completely normal response.

However, if the redness hasn't resolved after two weeks,

it may be worth considering a vascular laser (such as V-Beam) as a complementary option.

Leaving it untreated can cause it to become more persistent over time.

Q2. How many sessions are typically recommended, and how far apart should they be?

A. Most patients do well with 3–5 sessions spaced 3–4 weeks apart.

I've seen patients who saw no improvement after 10 sessions elsewhere

achieve satisfying results in just 2–3 sessions at our clinic

after recalibrating the depth and energy settings.

Ultimately, what matters isn't the number of sessions — it's whether the settings are right for you.

Q3. What should I absolutely avoid after my procedure?

A. For the two weeks following your procedure, avoid direct sun exposure

as well as hot saunas and intense physical exercise.

Consistent Sunscreen application in particular

is arguably the single most important factor in preventing PIH.

One more thing I always make sure to mention:

please avoid applying Retinol, AHAs, or any other

exfoliating actives immediately after your procedure.

Give your skin at least one week to recover first.

I always recommend taking the time for a thorough consultation before committing to any procedure.