What's best: Tretinoin 4x/week or Retinal Daily?
This is among the most asked questions. Let's explore the current evidence and see if we can hopefully find the answer.
Getting straight to the point, we don’t have a study directly comparing “tretinoin 4x/week” vs. “retinal daily” in the same subjects over 6-12 months. That would be the ideal evidence.
But what we do have is long-term robust efficacy and safety data on tretinoin and moderate efficacy with excellent safety data on retinaldehyde.
However, it is important to note that the evidence supporting the long-term effectiveness of retinaldehyde does not match the extensive data demonstrating tretinoin’s benefits for the skin.
Research on retinaldehyde has been somewhat limited, often involving shorter study durations, smaller groups of participants, and fewer detailed histological endpoints compared to what we see with tretinoin studies. But it is growing, so hopefully soon we will have more high-quality trials that will allow me to speak more confidently about retinal efficacy based on actual evidence, rather than relying on my own anecdotal success story with retinal.
One thing the studies don’t always capture: formulation matters massively.
A high-quality stabilised retinal product with penetration enhancers, a good stabilisation system or encapsulation technology and complementary actives ( like Medik8 Crystal Retinal or Sachi Skin , for example ) might actually deliver better real-world results than poorly formulated generic tretinoin cream - even though tretinoin is inherently more potent.
Think of it as comparing a well-engineered vehicle with advanced features to a more powerful but basic model: the former may perform better in daily use despite lower raw power.
You can find my list of the best OTC retinal serums here.
However, if you’re treating acne, this calculus changes entirely. Tretinoin will absolutely outperform retinal.
My Analysis: Which Is Better?
For most people starting out (first 6-12 months): Retinal daily probably wins.
Here’s why:
You’re getting 7 applications per week, up from 4, which means more consistent retinisation as you build results.
Comparable efficacy to tretinoin based on the Creidi study
Better tolerability = better adherence, and adherence is usually where retinoid routines fail doi: 10.1007/s12325-022-02319-7
This approach reduces the chance of irritation-induced PIH, which is especially helpful if you’re not pale or if you have particularly sensitive skin.
Tretinoin 4x/week makes more sense if:
You’re treating moderate-severe acne (prescription strength works better here 100%)
You’ve used retinoids before and know your skin can handle it
You’re working with a dermatologist who’s monitoring you
Cost matters—tretinoin prescriptions are often cheaper than quality retinal products.
Once you’ve achieved your results ( after 12 months ), the Olsen data shows 3x weekly tretinoin maintains them. Going 4x/week gives you a margin above the minimum threshold. At this point:
You’ve already done the hard work of building tolerance
Tretinoin is prescription-strength, but you’re using it less frequently, so side effects are minimal
It’s cost-effective long-term
The evidence base is stronger for intermittent tretinoin maintenance than for retinal maintenance.
My Bottom Line Recommendation.
If I were advising someone starting fresh:
Start with retinaldehyde 0.05-0.1% 3-4 times per week, gradually building tolerance to daily use. Continue this schedule for 3-6 months. Assess your results. If you’re happy with the improvements and tolerating it well, keep going.
If you want more intensity or aren’t seeing enough change, transition to tretinoin 0.025% 3-4 times per week.
If someone wants the aggressive route:
Tretinoin 0.025% 4 times per week from the start, especially if acne + photoaging are both concerns. However, adopt the “start low, go slow” strategy—perhaps begin with 2-3 times weekly during the first month.
Long-term (everyone, after 12 months of daily use):
Using tretinoin 3-4 times weekly is likely the most well-supported, budget-friendly maintenance approach. The evidence backing this is strong, and long-term user experiences also support it.
I hope you found the answer you were looking for or learned something new from this post.
This is always the ultimate reason I started posting on social media in the first place.
That’s it for this week.
Lots of love,
Marina x
I have enjoyed reading every bit of the post. The comparison offers an objective clarification on what’s out there and leaves the choice to the reader. Thank you so much! Xx