Creme De La Mer: Is It Worth it?

creme de la mer

After an experiment exploded in his face, NASA scientist Max Huber decided to create a cream to help heal his wounds. Creme De La Mer was born. In 1996, Estee Lauder bought it, and since then it has become a staple in many a celebrity’s beauty arsenal. J.Lo is said to love this stuff so much to stockpile huge amounts of it. And who could blame her? Surely, a cream developed by a NASA scientist must contain something pretty unique and incredibly effective, right? Well, not exactly…

What Creme De La Mer says

The original miracle, borne from Dr. Huber’s quest to heal his own skin’s scarred appearance. This ultrarich cream transforms skin on contact and soothes sensitivities. It helps heal even the driest complexions and dramatically renews skin’s appearance. Skin in any state will benefit from this nourishing treatment, but it is especially suited to very dry complexions. To this day, each opal jar is filled by hand to maintain its delicate balance.

Ingredient Analysis

algae extract

Seaweed (Algae) Extract

Seaweed extract is a very generic term. More than 20,000 species of algae exist and, even though only a bunch of those are commonly found in cosmetics, it’s hard to say which one Creme De La Mer uses. Most of them have emollient and antioxidant properties, but they aren’t the miraculous ingredients the brand claims them to be.

But the secret is, apparently, in the fermentation process. Nicki Zevola of Futurederm explains that “(ultrasound waves) are directed into the cream to ferment the algae, accelerating the rate by which algae produces lactic acid.” A Alpha Hydroxy Acid, Lactic Acid can dissolve the glue that holds skin cells together, allowing them to slough off. Once exfoliated, skin is smoother and brighter. There is no need to go through all this trouble to produce lactic acid though. It can be bought from many manufacturers.

glycerin molecular structure

Mineral Oil (Paraffinum Liquidum), Petrolatum, Glycerin

Mineral Oil and Petrolatum have gained a bad reputation because they are derived from oil. But before they can be used in skincare products, they must undergo a strict and rigorous purifying process that eliminates all their toxic components. What’s left is not only safe for us, but very moisturizing too.

Both ingredients work by creating a protective barrier on the skin that slows down water loss. Plus, they also have wound-healing properties. Glycerin, instead, is a humectant that draws water from the environment into the skin, increasing its hydration. This blend of ingredients makes this a very moisturizing formula, especially suitable for dry skin.



Creme De La Mer is infused with antioxidants, such as Medicago Sativa (Alfalfa) Seed Powder, Copper Gluconate (it can increase the levels of superoxide dismutase, a powerful antioxidant), and Tocopheryl Succinate, a very effective form of Vitamin E. Unfortunately whatever benefits these antioxidants may provide are nullified by the jar packaging. That’s because antioxidants lose a bit of their effectiveness when exposed to light and air, which happens every time you open the lid.

Final considerations on the formula

Creme De La Mer is a basic moisturizer with a very high price tag. It moisturizes skin, which will make it softer and look smoother and plumper. It also contains small amounts of copper and magnesium which could help heal wounds too, but while Dr Huber may have found them helpful, not many hurt their skin that bad or even just frequently to need a cream with such healing properties. I also don’t like the preservatives used. Methylchloroisothiazolinone and Methylisothiazolinone are too of the most irritating and can cause allergic reactions.

Full Ingredient List

Seaweed (Algae) Extract, Mineral Oil (Paraffinum Liquidum), Petrolatum, Glycerin, Isohexadecane, Citrus Aurantifolia (Lime) Extract, Microcrystalline Wax, Lanolin Alcohol, Sesamum Indicum (Sesame) Seed Oil, Eucalyptus Globulus (Eucalyptus) Leaf Oil, Magnesium Sulfate, Sesamum Indicum (Sesame) Seed, Medicago Sativa (Alfalfa) Seed Powder, Helianthus Annuus (Sunflower) Seedcake, Prunus Amygdalus Dulcis (Sweet Almond) Seed Meal, Sodium Gluconate, Potassium Gluconate, Copper Gluconate, Calcium Gluconate, Magnesium Gluconate, Zinc Gluconate, Paraffin, Tocopheryl Succinate, Niacin, Beta-Carotene, Decyl Oleate, Aluminum Distearate, Octyldodecanol, Citric Acid, Cyanocobalamin, Magnesium Stearate, Panthenol, Limonene, Geraniol, Linalool, Hydroxycitronellal, Citronellol, Benzyl Salicylate, Citral, Methylchloroisothiazolinone, Methylisothiazolinone, Alcohol Denat., Fragrance


Creme De La Mer is available at Nordstrom and Harrods. A 30ml jar costs a whooping $160!

The bottom line

Creme De La Mer is an effective, but very basic, moisturizer that’s particularly suitable for dry skin. If you like the formula and can afford it, go for it. But don’t expect miracles. There’s nothing revolutionary or unique here that justifies its high price tag. On the contrary, its active ingredients are commonly used in many, and much cheaper, skincare products.

Have you ever tried Creme De La Mer? If so, what do you think of it?

Do You Have Dry, Acne-Prone Skin? Here’s How To Deal With It

how to deal with dry acne prone skin

We tend to think of acne as something that can occur only to those with oily skin, but that’s not true. If you have dry skin, you can be plagued with it as well. Often, this dry skin is self-inflicted. In an effort to get rid of acne, you can go too far, drying out your skin and damaging it even more. But other times, your skin was already, maybe has always been, dry, when you started developing acne.

In either case, having to deal with both acne and dry skin at the same time can be very confusing. How do you treat both conditions without making things worse? Let’s start by figuring out the cause:

1. Harsh anti-acne and anti-aging ingredients

Anti-acne ingredients such as Salicylic Acid (it penetrates inside the pores, exfoliating them from within), Benzoyl Peroxide (it can kill the bacteria that causes acne), or Differin (it accelerates cell turnover) are very effective at keeping this condition under control but, if used in high doses or too often can irritate skin and drying it out.

Some people use two or more of these ingredients at the same time, sometimes even adding OTC retinoids and Vitamin C to the mix to help fight premature aging as well. While your skin needs antioxidants to stay young and healthy, these particular ingredients can also cause irritations when used too often or in too high doses.

The solution? Experiment to find the anti-acne routine that works best for you. You can use a BHA exfoliant with salicylic acid during the day and retinoids at night. Or you can use retinoids only every other day, alternating them with benzoyl peroxide. Also consider reducing the doses of these active ingredients. Rather than using a 10% BHA exfoliant, for instance, opt for a 2% concentration. Some people cannot use these ingredients at all because any concentrations make their skin act up. In that case, replace BHA exfoliants with AHAs ones and OTC retinol products with antioxidant rich serum. For alternatives to prescription products, consult your doctor.

2. Harsh skincare products

Even if you’ve found the right anti-acne or anti-aging products, you may be using something else that makes your skin act up. Avoid bar soaps and harsh cleansers, in particular those with Sodium Lauryl Sulfate, that can strip too much oil from your skin. Oil is the skin’s natural moisturizer so, while removing any excess is good, getting rid of it completely can dry it out even more. Instead, opt for cleansers with gentler surfactants, such as Boots Expert Anti-Blemish Cleansing Foam or Paula’s Choice Clear Normalizing Cleanser Pore Clarifying Gel.

Not everyone needs toner, and certainly no one needs those loaded with alcohol, witch hazel, or menthol. They just dry out or irritate skin even more. And so do harsh scrubs that remove dead skin cell with the help of apricot or walnut seeds. Their jarred edges can tear at the skin, irritating it. The Clarisonic brush, if used too often, can make things worse as well. For exfoliation, stick to BHA, or, if that irritates your skin, AHAs exfoliants, which are gentler on the skin.

If your skin is dry, you may be tempted to use rich moisturizers. But if your dry skin is caused by the wrong skincare products or by abusing good ones, a moisturizer that’s too rich won’t help much. It may actually make things worse. How? A lot of the heavy moisturizing and thickening ingredients used in them can clog pores and exacerbate breakouts. Instead, opt for a lightweight gel formula loaded with antioxidants such as MD Formulations Moisture Defense Antioxidant Hydrating Gel. And don’t even think of skipping sunscreen! Your skin will never heal if you keep inflicting sun damage on it too every day.

Finally, keep in mind that any skincare products, including those formulated for acne-prone and/or dry skin, can contain any of the harsh ingredients already mentioned, such as alcohol, sodium lauryl sulfate, or menthol. So always read the ingredient list carefully before purchasing a skincare product or you may risk throwing money away on something that will make your problems worse, not better.

What if you still have dry skin and acne?

What if there’s nothing wrong with your skincare routine but your skin is still dry and acne-prone? Your dry skin may be due to other causes, such as cold weather and low humidity that can suck all the moisture out of your skin. Genetics, aging, and medical conditions such as thyroid disease can play a part too.

If your skin is really acne-prone and dry, all the tips above bar one apply. A lightweight gel moisturizer may not be enough for your skin type. Only in this case, you should opt for a richer formula. Just make sure it doesn’t contain any of the irritating ingredients mentioned above. Stay away from moisturizers with mineral oil as well. Although cosmetic grade mineral oil isn’t comedogenic, it can still exacerbate acne in some people.

Dealing with both acne and dry skin can be frustrating, but with the right products and skincare habits, you too can get clearer, softer, and more hydrated skin.

Do you suffer from both acne and dry skin? If so, how do you deal with them?

Why Philosophy Hope In A Jar Leaves You Hoping For More

philosophy hope in a jar

Who has never heard of Hope In A Jar by Philosophy? This lightweight moisturizer has achieved cult status and has a loyal legions of fans swearing by it. But I’m not one of them. Here’s why:

What Philosophy Says

our award-winning, lightweight daily moisturiser hydrates and provides antioxidant protection while improving skin texture and tone, leaving it smooth and radiant. this high-performing moisturiser contains lactic acid, a gentle alpha hydroxy acid that helps remove surface dead skin cells and beta-glucan to promote overall skin health by helping to strengthen skin’s natural rejuvenation potential. hope in a jar dramatically improves skin radiance and gently exfoliates, revealing smoother, healthier looking skin and texture.

Ingredient Analysis

sodium lauryl sulfate chemical structure

Lauryl Lactate

Philosophy claims that Hope In A Jar contains the exfoliant lactic acid, but unfortunately that’s not true. Instead, it contains an easter form of lactic acid, lauryl lactate. Lauryl Lactate can’t be converted into lactic acid, and it doesn’t have its same properties either. That means that it can’t exfoliate skin, but only enhance the spreadability of the cream onto the skin and prevent the oil and water parts of the formula from separating. Pretty disappointing, huh?

glycerin molecular structure


Glycerin is a humectant that can draw water from the environment into the skin, increasing its hydration and preventing water loss. Plus, it can strengthen the skin’s barrier. As a result, skin is softer, and more supple and hydrated.


Retinyl Palmitate

A form of Vitamin A, Retinyl Palmitate is a combination of retinol and palmitic acid. Like all forms of Vitamin A, it has antioxidant properties. But, because it is gentler than retinol, it is also less effective. Before it can work its magic, retinyl palmitate must be converted first into retinol, then into retinaldehyde, and finally into retinoic acid. At the low concentration included here, it is doubtful how effective it would be after all these conversions. Packaging is another problem. The jar exposes retinyl palmitate to light and air, which spoils it overtime, making it ineffective. In any case, women who are either pregnant or nursing shouldn’t use any form of Vitamin A.

Final considerations on the formula

The first ingredients are those that make up most of the formula and are therefore the most important. In Hope In A Jar, they are mainly hydrating and thickening agents that make skin soft and smooth and give the product its consistency. The few antioxidants, such as Tocopheryl Acetate, a form of Vitamin E, in the formula are present only in very small concentrations and, while that’s always better than nothing, the jar packaging won’t keep them stable and effective for long.

Full ingredient list

Water, Lauryl Lactate, Behenic Acid, Behenoxy Dimethicone, Glycerin, Glyceryl Stearate Se, Behenyl Alcohol, Pentaerythrityl Tetracaprylate/Tetracaprate, Clyclopentasiloxane, Tocopheryl Acetate, Benzyl Alcohol, Retinyl Palmitate, Stearic Acid, Panthenol, Betaglucan, Lavandula Angustifolia (Lavender) Oil, Xanthan Gum, Triethanolamine, Propylene Glycol, Methylparaben, Propylparaben, Diazolidinyl Urea


Although I don’t recommend it, you can buy Philosophy Hope In A Jar at Sephora. It is available in three sizes: 0.5oz ($15.00), 2oz ($42.00), and 4oz ($67.00). Keep in mind that the bigger the packaging, the sooner the antioxidants will oxidize (ie become ineffective).

The Bottom Line

Philosophy Hope In A Jar is a basic moisturizer that hydrates skin but can’t exfoliate it. Its antioxidant properties are minimal too. At this price point, a moisturizer should do a lot more imo. I wish Philosophy updated the formula to include effective exfoliating agents and a higher concentration of antioxidants, and packaged it in a tube or bottle, but, considering how popular it already is, it is unlikely it will.

Have you tried Philosophy Hope In A Jar?

Is St Ives Timeless Skin Collagen Elastin Facial Moisturizer Really As Good As Dr Oz Claims?

st ives timeless skin collagen elastin moisturizer

Just because a doctor recommends something, it doesn’t necessarily mean that it is good. A few years ago, Dr Oz urged his viewers to put away their expensive and fancy creams and buy St Ives Timeless Skin Collagen Elastin Facial Moisturizer instead. Now, I agree with him that a lot of these fancy moisturizers are poorly formulated and way too overpriced, but I wouldn’t suggest the St Ives moisturizer as an alternative. Why? Its formula is SO dated.

What St Ives Says

This moisturizer, with collagen elastin proteins, hydrates for visibly softer, smoother skin.

Ingredient Analysis

mineral oil cosmetics

Mineral Oil

Mineral oil has gained a bad reputation because it is derived from oil. But cosmetic grade mineral oil, the only type allowed to be used in cosmetics, has been highly purified. All the nasty stuff has been taken out of it, making it safe for use.

Mineral oil is an occlusive skin conditioning agent. It works by creating a barrier that prevents water loss, thus helping skin stay hydrated. Because of this, it is a great choice for dry skin.

Although mineral oil, on its own, isn’t comedogenic, it can cause breakouts when used with pore-clogging ingredients. That’s because it traps them beneath the barrier it creates. So, if you use it with other non-comedogenic products, you shouldn’t experience any side effects.


Propylene Glycol

Propylene Glycol is another ingredient with an undeserved bad rep. It is true that, at 100% concentrations, it is an anti-freeze, but of course, no one puts that much into a cream! In cosmetics, where it is used in minuscule amounts, it is used as a humectant, which means it can attract water from the environment into the skin, helping to keep it hydrated. Propylene Glycol can also help other ingredients better penetrate into the superficial layers of the skin, although mineral oil may actually block that from happening.


Collagen and elastin

Collagen and elastin work together to keep skin elastic and smooth, but, when used in a lotion, they don’t have any anti-aging properties. That’s because their molecules are too big to penetrate the skin, so they just rest on its surface and hydrate it. That’s it.

Final considerations on the formula

Is St Ives Timeless Skin Collagen Elastin Facial Moisturizer a good moisturizer? Yep. Problem is, moisturizing skin is all it does. The formula doesn’t contain antioxidants, nicinamide, retinoids, sunscreen agents, or ahas, all ingredients proven to help skin remain healthy and look younger for longer. Twenty years ago, this may have been a decent formula, but in 2014, a cream should do more than just hydrate skin, even at this low price point. And the jar packaging? I usually don’t like it because it doesn’t keep light-sensitive ingredients effective for long, but there’s nothing in here that can go bad when exposed to light and air.

Full ingredient list

Water (Aqua, Eau), Mineral Oil (Paraffinum Liquidum, Huile Minerale), Propylene Glycol, Glyceryl Stearate, PEG-100 Stearate, Stearic Acid, Phenoxyethanol, Carthamus Tinctorius (Safflower) Seed Oil, Triethanolamine, Carbomer, Cetyl Alcohol, Dimethicone, Disodium EDTA, Fragrance (Parfum), Ethylhexylglycerin, Hydrolyzed Collagen, Hydrolyzed Elastin, Linalool, Hexyl Cinnamal, Coumarin, Geraniol


St Ives Timeless Skin Collagen Elastin Facial Moisturizer is available at amazon and walgreens. A 10 oz jar costs only $5.44.

The Bottom Line

St Ives Timeless Skin Collagen Elastin Facial Moisturizer is a very basic moisturizer. It will hydrate your skin, but don’t expect anything more. That’s why I recommend this cream only to acne-free teenagers who have great skin to begin with,and aren’t yet interested in anti-aging creams, and only have a small budget to satisfy their skincare needs.

Have you tried St Ives Timeless Skin Collagen Elastin Facial Moisturizer? If so, what do you think of it?

5 Things I Learned About Skincare

skincare lessons learned

I cringe when I remember the damage I inflicted on my skin as a teenager. Harsh toners, no sunscreen, moisturizers too rich for my skin type that made me break out horribly. Eventually, I learned how to take care of it, but it wasn’t until I started blogging that my knowledge about all things skincare expanded immensely. Here’s what I learned along the way:

1. It’s the dose that makes the poison (or the elixir)

It’s not just about what ingredients are in a product, but in what concentrations too. So many skincare products contain plants extracts or vitamins that are supposed to be beneficial for the skin, but, in the minuscule concentrations they’re used, are pretty much useless. On the other hand, ingredients that are dangerous at high doses are perfectly safe when used in minuscule amounts. 100% Propylene Glycol is an antifreeze that can be very irritating, but in cosmetics, where it serves as a humectant and penetration enhancer, it is used in such tiny doses to be harmless. Vitamin C is a powerful antioxidant that does wonders for the skin, but if you ingest too much, it could kill you. Nothing is either bad or good. It just depends on the dose.

2. Packaging matters

I have always been a sucker for pretty packaging. When I was younger, I often impulse bought something because it looked so good on the shelf. These days, packaging is still one of the main deciding factors when I purchase something. But now, rather than to aesthetic, I’m drawn to functionality. A lot of the best beneficial skincare ingredients, such as retinoids, antioxidants, and sunscreen actives, lose a bit of their effectiveness whenever they are exposed to light and air. So, they must be packaged in air-tight and opaque tubes and bottles. Otherwise, you’re just throwing your money away.

3. Stick with the purpose products are formulated for

Of course, there are exceptions to this rule. If I don’t like a face moisturizer, I will use it on my body. But I would never do the opposite. Why? Because body care products tend to have heavier consistencies that moisturize the thicker skin of our bodies well, but could easily cause havoc on our faces. And using anything on your skin that hasn’t been formulated for it is a no-no. Dishwashing liquids may contain the same cleansing agents as those in your shampoo or body wash, but the concentrations are higher and harsher, and could seriously dry and irritate your skin. Milk Of Magnesia can seem a godsend for oily skin, but its ph is way too high and could cause all kinds of troubles. Yes, there are times when a brand just packages the same formula in different bottles and charges you double for it (for instance, a lot, but by no means all, eye creams are just facial moisturizer in tinier but more expensive jars), but often, there is a very good reason why a product is labelled for a certain use, so stick with it.

4. Skin is more useful than we think

Our society puts a lot of emphasis on the way we look, so it’s easy to believe the only purpose of our skin is to look good. But skin does a lot more than that. Its main job is to keep stuff OUT of the body, and it is incredible good at that. Think about what happens (or better, doesn’t happen) when you have a shower or a bath. Your body doesn’t soak up all the water, does it? Yet, there are people who would have us believe that everything we put on our skin penetrates it. On the contrary, very few substances are able to get through it. Most stay on the surface or, if they manage to get through, only remain in the superficial layers of the skin, never reaching the blood stream. And why should cosmetic ingredients be able to penetrate so deep into the body, anyway? Their purpose is to beautify and take care of the skin, so they’d need to stay in the zone to do their job properly.

5. You don’t need that many skincare products

Cleanser, toner, facial moisturizer, eye cream, serum, mask, exfoliant, sunscreen… There are so many skincare products we’re told we need, but that’s not true. What your skin needs depends on its problems and concerns. At 31, my skin is pretty good, just a bit oily on the t-zone. My main concern, now, is anti-aging. So, in the morning, I use a cleanser, a serum with antioxidants, a moisturizer, and a sunscreen. At night, a cleanser, a serum with retoinds, and an antioxidants-rich moisturizer. A few times a week, I exfoliate, and whenever I feel like it, or my skin needs an emergency pick-me-up, a mask too. Toner? I don’t need it. Eye cream? Nothing can cure my genetic dark circles so I just apply my fragrance-free facial moisturizer on the eye area. Works just fine. Only if the skin around your eyes is different from the skin of the rest of your face, or has a particular concern, should you invest in a separate eye cream.

Rather than purchasing any type of product out there, figure out what problems your skin has, what ingredients can solve it, and choose products accordingly. Only cleanser, moisturizer, exfoliant, and sunscreen are an absolute must for everyone. If you need more (such as anti-acne, anti-aging, or anti-hyperpigemntation products), add more. But don’t buy a toner, or something else, because you think your skincare routine will be incomplete without it, or you may be throwing money away on stuff that does nothing for your skin.

What have you learned about skincare?

Are You Reducing The Effectiveness Of Your Sunscreen?

sunumbra sunkids spf 40

We can spend hours looking for the right sunscreen that won’t feel too greasy or leave a white cast on our skin. We read the labels carefully to make sure it provides broad-spectrum protection. And, often, in the summer, we opt for products with high SPF numbers that promise to keep our skin protected for hours.

But it doesn’t matter how good the sunscreen we bought is if you we don’t apply it properly. If you think you can just pour out a bit of product, slather it on your face, and go about your day without reapplying it, think again. Sunscreen application has its own rules and, if you break them, you’re seriously reducing the effectiveness of your SPF.

Here are a few tips to avoid that:

1. Apply sunscreen first, get dressed later

Sunscreens should be applied at least 20 minutes before going out. So, why not apply it right after your shower? By applying sunscreen while naked, you won’t miss any spots, not even those hard-to-reach-and-easy-to-forget-about ones such as your feet and the back of your neck. We also tend to apply less sunscreen on the areas around sleeves etc for fear of staining our clothes. By applying sunscreen before getting dressed, your clothes won’t hinder you.

skincare product time

2. The proper order

Zinc Oxide and Titanium Dioxide create a shield on the skin that reflects sun rays away from it. These can be applied at anytime. All other sunscreen agents, such as Avobenzone and Octocrylene, for instance, need to bind with the skin in order to provide sun protection. Therefore, they should be applied first, before moisturizer and makeup.

3. Apply the proper amount

I know, I know. A lot of sunscreens are pasty, thick, and leave a white residue behind. But that’s not an excuse to apply a thin layer and expect it to protect you for hours. In fact, that won’t offer much protection at all. Instead, shop around until you find a sunscreen that fits all your requirements and apply the proper amount. That’s a shot glass for the whole body and a 1/2 of teaspoon for the face and neck. If you use a zinc oxide-based sunscreen, you can use a bit less. But in no case a thin layer is enough. Ever.

4. Follow instructions

Let’s face it. Often, the directions printed on the back of beauty products are odd and absurd. Use the shampoo only with its matching conditioner? Apply the cream with a weird massaging technique that’s supposes to help the ingredients penetrate better into the skin? Usually, this stuff is there to make you think these products do something their competition doesn’t and nothing more. But, other times, the instructions are actually very helpful and should be followed to a T. Otherwise, you’ll just compromisethe effectiveness of the products. That’s the case with sunscreen. Always apply the recommended amount printed on the label, and reapply every couple of hours, and always after swimming, sweating, and towel-drying.


5. Don’t rub it in!

If you’re vigorously rubbing sunscreen into your skin, stop! A 2006 study has shown that sunscreen works better when it is applied as a thin film than when it is rubbed into the skin. Now, thin film doesn’t mean that you can apply less than the recommended amount. That is NEVER a good idea. Instead, it means that after you’ve covered all areas, you should feel a thin film on the skin.

6. Don’t dilute it!

Some people like to mix their sunscreen with their moisturizer to create a 2 in 1 product that does it all. In reality, rather than protecting your skin, you are damaging it. By mixing the two together, you’re diluting your sunscreen. That means that you’ll have to apply more to have the level of protection stated on the bottle! And no one does that. Not to mention that your moisturizer may contain some ingredients that can compromise the effectiveness of the sunscreen. So, just use two separate products. Better be safe than sorry.

7. Don’t use sunscreen with insect repellant

Mosquitoes must be, by far, the worst thing about summer. But covering yourself in insect repellant while at the beach (or whenever you’re wearing sunscreen for that matter) is not a good idea. A 2000 study has shown that, while the effectiveness of the insect repellant isn’t diminished when used with sunscreen, the active ingredient used in insect repellant, N,N -diethyl-3-methylbenzamide (diethyltoluamide; deet), can reduce by 33.3% the effectiveness of sunscreen. This happens even if you layer the products one after the other. Therefore, use them together only if absolutely necessary.

Are you inadvertently reducing the effectiveness of your sunscreen?