WTF are... sebaceous filaments anyway?

Blackheads' misunderstood cousin; find out more about these confusing little bastards

Nov 04, 2025

So… WTF are they?

Sebaceous filaments are natural, tube-like structures in your pores made of:

Sebum
Dead skin cells
Bacteria

They are most visible in areas with high sebum production, eg your T-zone (forehead, chin, nose), your scalp, and back.

What’s the point of them? I mean, what do they actually do?

So first, a few words on sebum. It’s usually talked about the context of acne/pimples and is often perceived as The Big Bad Wolf of secretions.

Sebum is actually doing all of the following for your skin:
1. Moisture retention and barrier protection

It forms a film over the skin’s surface to prevent water loss and helps form your acid1 mantle; a thin film that keeps bacteria, fungi, pollution and irritants out.

2. Antimicrobial defence and antioxidant support

Elements of sebum have mild antibacterial and antioxidant properties, eg squalene2.

3. Lubrication

It helps keep hair and skin soft and flexible

Yay sebum!

Sebaceous filaments are tiny sebum transport systems that help move oil from your sebaceous glands through the follicle/pore to the skin’s surface3.

You can see them in high-oil areas when:

The pore is large or stretched4
The density of the oil makes it appear darker
There’s more keratin in the mix
Under unforgiving lighting

Teenagers are particularly prone to them as their oil production is often booming.

But wait, what’s the difference between a sebaceous filament and a blackhead then?

I. AM. SO. GLAD. YOU. ASKED.

Sebaceous filaments are supposed to be there. They’re like your sebum arteries.

Blackheads are the visible evidence of a blocked pore.

I made you this to help56:

And here is a handy visual aid:

So, is treatment pointless?

The bad news: If you have visible sebaceous filaments - and many people do - you’re unlikely to be able to totally eradicate them.

The good news: you can minimise their visibility with the following

Salicylic acid (BHA): Unclogs pores, dissolves oil and debris.
Retinoids7: Regulate cell turnover, reduce clogging.
Niacinamide: Balances oil production
Clay masks (no more than twice a week)8: Absorb surface oil temporarily.
Oil cleansing: There is anecdotal evidence9 that massaging an oil cleanser into your pores for 2+ minutes helps to purge sebaceous filaments
I very rarely write about the efficacy of the sun in skincare, because it’s a can of worms that I’m just not ready to open for now, but my sebaceous filaments become significantly less visible with regular sun exposure10
Make-up, obvs.

Do not

Squeeze them as part of your routine - this can damage the pore wall, and they’ll just fill back up within a couple of weeks
Use pore strips on sebaceous filaments. You might get some fun dots on the strip, but this is just surface sebum and it’s likely to disregulate the filaments11

Anything else I think you should know?

I did you A GRID. What more do you want from me?!

But I would like to reiterate that sebaceous filaments and blackheads are different badgers, and you shouldn’t automatically apply blackhead remedies to sebaceous filaments.

AND you don’t need to ‘treat’ them unless you want to. They’re part of how your skin works, and they’re doing a really good job for you 🥰.

Until the next time! x

If you have a concern that I’ve irresponsibly included/omitted information, don’t hesitate to get in touch to let me know and I’ll take a look.

Reminder that any cosmetic work undertaken should be in accordance with The 6 rules of cosmetic work. Here they are, in case you missed them the first time…

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It can’t be just me who hears this every time they see the word ‘acid’?