Vitamin C or Niacinamide: Which Serum Should Men Start With?

Vitamin C and niacinamide fix different problems. Here is how to pick the right serum for your skin, and why you do not have to choose only one.

By Abhishek Jain 22 Sep 202613 min read

Illustration of a young Indian man on an apartment balcony at dusk, looking at two small serum bottles in his hands, one in each palm

Start with the serum that matches your main problem. Oily skin, pimples, open pores and pimple marks point to niacinamide. Tan, dullness and dark spots from the sun point to vitamin C, and you can use both.

It is 4 pm in the office washroom. The mirror shows a forehead that could guide traffic at Silk Board. There is a fresh pimple near the nose, and a dark mark where last month's pimple used to be.

So you open the app. Two serums sit in the cart. One says vitamin C. One says niacinamide. Both have four and a half stars. Your cousin's wedding is in three weeks.

Here is the short answer.

Niacinamide helps with oil, shine, open pores and the marks pimples leave behind.
Vitamin C helps with tan, dullness and dark spots from the sun.
Pick one serum for your biggest problem. Use it daily for a month before you judge it.
The two do not cancel each other out. You can use both.

Now the detail, and the proof.

What Is the Difference Between Vitamin C and Niacinamide?

Think of the colour in your skin as a delivery business. Cells called melanocytes are the factory. They make melanin, the pigment behind tan and dark spots. Then they hand it over to the skin cells around them. Vitamin C and niacinamide act on different ends of that business.

Vitamin C slows the factory. A review in the Indian Dermatology Online Journal explains how. It blocks tyrosinase, the enzyme that makes melanin. The same review calls vitamin C the most plentiful antioxidant in human skin. An antioxidant mops up the unstable molecules that sun and pollution create. A second review lists sun, pollution and smoking as the causes of that damage.

Niacinamide, a form of vitamin B3, slows the delivery. A trial in the British Journal of Dermatology found it had no effect on tyrosinase. Instead, it cut the hand-over of pigment to skin cells by 35% to 68% in the lab. In Japanese women, 5% niacinamide reduced dark patches after 4 weeks.

Niacinamide has a second job, and it matters for men. A review of male and female skin found men's skin makes more sebum, the oil your skin produces. It is also thicker. Niacinamide turns the oil tap down. In a trial on 100 Japanese volunteers, 2% niacinamide lowered oil output. The drop showed within 2 weeks. That is why THERŌ built its oil control range on it, and its brightening range on vitamin C.

Diagram of a melanocyte, the branched pigment cell in skin, with melanin granules moving out along its arms, and a pie chart of melanin types — The pigment factory. The blue cell is a melanocyte, and the small brown dots are melanin packets travelling out along its arms to the skin cells around it. Vitamin C slows the factory. Niacinamide slows the deliveries. (Photo Credit: Ewelina Mazur, Dominika Kwiatkowska and Adam Reich, Wikimedia Commons, CC BY 4.0)

Is Niacinamide Good for Men With Oily Skin and Pimples?

Yes, and the evidence is solid. A 2024 review found that 2% to 5% niacinamide reduced sebum in several clinical studies. The volunteers were Asian and white. An Indian review in IJDVL describes a trial of 160 people with acne. The 4% niacinamide group had a greater drop in oiliness scores than the antibiotic group.

Pores shrink in appearance too. A 2021 review reports a split-face trial where 4% niacinamide reduced pores after 8 weeks.

Pimples respond as well. In a trial of 76 people, a 4% niacinamide gel matched a 1% clindamycin antibiotic gel over 8 weeks. Improvement was 82% with niacinamide and 68% with the antibiotic. A later trial of 80 people found niacinamide worked better on oily skin types. That is most Indian men in most months.

Then there are the marks. In the British Journal of Dermatology trial, dark patches faded in 4 weeks. In 50 women who used 5% niacinamide twice a day for 12 weeks, dark spots and blotchiness reduced.

THERŌ's niacinamide serum uses 5% niacinamide. Salicylic acid, mandelic acid and green tea back it up. It helps control excess oil, refine the look of pores, and reduce the appearance of post-acne marks. If pimples are the main issue, the acne control collection groups the full set.

THERŌ Active Oil Control Niacinamide Serum in an amber dropper bottle with green tea leaves and a splash of water — THERŌ's oil control serum carries 5% niacinamide, the same strength range the trials above used. The green tea is on the label, not in the cup. (Image: THERŌ)

Is Vitamin C Good for Men With Tan and Dark Spots?

Yes. A 2023 systematic review pooled seven trials with 139 volunteers. It found vitamin C reduces pigment and improves uneven skin, with long-term use. A Mexican trial ran 5% vitamin C cream against hydroquinone for 16 weeks. Hydroquinone is a prescription pigment drug. Instruments measured no difference in colour. Side effects were 6% with vitamin C and 69% with hydroquinone.

Strength matters. The same review that named the causes of damage puts the useful range above 8% and up to 20%. Above 20% adds irritation, not results.

Vitamin C also helps your sunscreen. The Indian review notes that sunscreen blocks only 55% of the free radicals made by UV. Vitamin C in the skin catches part of the rest. That is useful on a two-wheeler at noon in May.

THERŌ's vitamin C serum uses 10% stabilised vitamin C. Kojic acid and alpha arbutin, two more pigment blockers, ride along. Visibly brighter skin in 4 weeks. It sits in the sun damage collection with the face wash and moisturizer of the same range. For the full picture, read what a vitamin C serum does for men.

THERŌ Intense Bright Vitamin C Serum in a dark amber dropper bottle — THERŌ's vitamin C serum pairs 10% stabilised vitamin C with kojic acid and alpha arbutin. The dark bottle keeps light out, because light is what turns vitamin C yellow. (Image: THERŌ)

Can You Use Vitamin C and Niacinamide Together?

Yes. The idea that they cancel each other out is a myth. A skin of colour review notes that niacinamide is stable in light, moisture, acids and alkalis. The Indian review says vitamin C is safe with sunscreen, antioxidants and glycolic acid. The 2021 niacinamide review lists trial formulas that pair the two. In one 8-week split-face trial, a combined formula reduced melanin readings.

The simplest proof is in the bottle. THERŌ's vitamin C serum already contains niacinamide. It keeps oil in check while the vitamin C works on tan. So a man with tan and an oily T-zone does not need two bottles on day one.

If you own both serums, do not stack them. A Cleveland Clinic dermatologist advises one serum at a time. Use vitamin C in the morning, because it backs up your sunscreen. Use niacinamide at night. Your skin gets both, and your bathroom shelf stays calm.

How Should Men Use a Serum? A Simple Routine

Serums are step two of the four THERŌ steps: Cleanse, Treat, Moisturise, Protect. Morning and night look like this.

Cleanse. Wash with a face wash and lukewarm water. Oily skin gets a niacinamide face wash. Dull, tanned skin gets a vitamin C face wash.
Treat. Put 3 to 5 drops of your serum on a clean face and neck. Pat it in until it is absorbed. Both THERŌ serums use the same amount.
Moisturise. A light moisturizer for oily skin or a vitamin C moisturizer. Both carry DustShield, a layer that helps fine dust stick less easily. Useful on a Delhi commute in November.
Protect. Sunscreen every morning, as the last step. Dark spots get darker in the sun, so skipping this step wastes the serum.

New to actives? Follow the AAD's patch test: a small amount on the inner arm, twice a day for 7 to 10 days. Harvard Health adds that a mild tingle from vitamin C is normal, and you can start every other day.

Illustration of an Indian man in a gym changing room patting a clear serum onto his cheek with two fingers, a locker and a towel behind him — Three to five drops, patted in after the face wash. Post-gym is a fine time, as long as the sunscreen goes on before you step outside. (AI-generated image)

Vitamin C and Niacinamide Myths That Waste Men's Money

"Vitamin C at night is dangerous." No. A Cleveland Clinic dermatologist says it is safe overnight. Morning is preferred because it backs up sunscreen. The Indian review even argues for using it after sun exposure, not before.

"More actives means faster results." The 2017 review found vitamin C above 20% adds irritation, not benefit. Two serums on day one is how men end up with a red face and a drawer of half-used bottles. One serum, one month.

"Niacinamide is a whitening cream." People search "niacinamide or vitamin C for skin whitening". Neither ingredient changes your natural colour. They reduce the look of tan, dark spots and uneven tone, so your skin looks like your skin again. That is the whole promise.

"The cream from the chemist works faster." Often that cream is a steroid. An IJDVL study of 2,926 patients at 12 Indian centres found 15% were using steroid creams on the face. Most had been told to by a friend or the chemist, and 29% used them as a fairness or general cream. Steroids need a prescription for a reason.

"Sunscreen is for the beach." A Mumbai survey found 61% of people had not heard of sunscreen. Yet DermNet says sun makes dark marks darker. The AAD says dark-spot treatment begins with sunscreen. Both serums work better under it. See products built for sun damage for the rest of the routine.

How Long Do Vitamin C and Niacinamide Take to Work?

Give either serum a month before you judge it. Here is what the trials saw, and when.

Less oil: 2% niacinamide, 2 weeks, 100 Japanese volunteers.
Lighter dark patches: 5% niacinamide, 4 weeks, 18 Japanese women.
Smaller-looking pores: 4% niacinamide, 8 weeks, a split-face trial cited in the 2021 review.
Fewer dark spots: 5% niacinamide, 12 weeks, 50 white women.
Even tone, less pigment: vitamin C, long-term use, 139 volunteers across 7 trials.
Visibly brighter skin: THERŌ's 10% vitamin C serum, about 4 weeks, product page.

Dark spots are slow. The AAD says a spot a few shades darker than your skin fades in 6 to 12 months. The skin of colour review says untreated marks can last months to years. So a month of serum will not erase a two-year-old mark. It will make the next one fade faster, if the sunscreen is on. Harvard Health puts a visible vitamin C change at up to three months. The serum collection has both options when you are ready.

When Should You See a Dermatologist?

A serum is a cosmetic, and some skin problems need a doctor. See a dermatologist if:

Your pimples are deep, painful or leaving pits. That is a medical condition, not an oil problem.
Dark patches appeared fast, spread, or sit in a butterfly shape across the cheeks. That may be melasma, which needs a diagnosis.
Any product causes burning, swelling, a rash or peeling that does not settle in a day.
Nothing has changed after 8 to 12 weeks of daily use with sunscreen.
You have been using a cream from the chemist that made your skin thin, red or easy to bruise. Stop and get it checked.

Never buy a steroid or "fairness" cream over the counter for your face. The IJDVL numbers above are what that habit does to Indian skin.

Vitamin C vs Niacinamide for Men: Common Questions

Should I apply vitamin C first or niacinamide first?

Do not layer two serums on the same face at the same time. A Cleveland Clinic dermatologist recommends one serum at a time. If you have both, use vitamin C in the morning under sunscreen and niacinamide at night. If you want both in one step, THERŌ's vitamin C serum already contains niacinamide.

Can men use niacinamide serum?

Yes. Niacinamide's best evidence is for oil, and men's skin makes more oil than women's, per a review of male and female skin. The oil control range is built around it for exactly that reason.

Why avoid vitamin C at night?

You do not have to. Cleveland Clinic calls night use safe. Morning is the smarter slot because vitamin C reinforces sunscreen. If your mornings are a sprint to the 8.12 local, use it at night rather than not at all.

Which is better for pimple marks, vitamin C or niacinamide?

Both have trial evidence for dark marks. Niacinamide has the faster data, with a change at 4 weeks in Japanese women. If the marks came from pimples and your skin is oily, start with niacinamide. If the marks came from sun and your skin is dull, start with vitamin C. Both need daily sunscreen to hold the result.

What should you never mix niacinamide with?

Niacinamide is the easy one. The skin of colour review notes it is stable with acids, alkalis and light. The 2024 review reports no irritation up to 5%. The real mistake is adding several new actives in one week. Add one product at a time, patch test it, and give it a month.

Is niacinamide or vitamin C better for tan?

Vitamin C, for tan from the sun. It slows the enzyme that makes melanin and mops up the damage that sun and pollution cause, per the Indian review. The brightening collection carries the vitamin C face wash, serum and moisturizer. Sunscreen does the other half of the job.

Vitamin C or Niacinamide: Which Should You Start With?

Look in the mirror at 4 pm. If you see shine, pimples, open pores and pimple marks, start with THERŌ's niacinamide serum. If you see tan, dullness and dark spots from the sun, start with THERŌ's vitamin C serum. It brings niacinamide along. Three to five drops after your face wash, moisturizer over it, sunscreen every morning.

Give it a month. Then decide whether you need the second bottle. Most men do not need it in month one. The bestsellers page shows which serum other men picked first. Handy if you want a second opinion that is not your cousin.