How to control oil for oily skin? The principles and methods of oil control

Keeping the skin with the right amount of oil, moisturized and soft, but not too greasy, is what you and I want. This article shares with you the main factors that affect oil secretion, the main methods of oil control, and answers some questions about oil control.

1. The main factors affecting oil secretion

1. Androgens

Current research suggests that the sebaceous glands of the hair follicles are mainly affected by androgens. Androgens mainly come from the gonads and, in adults, also from the adrenal glands. Testosterone takes effect after being converted into dihydrotestosterone (DHT), in which 5α-reductase plays a key role.

When androgen secretion is vigorous, the sebaceous glands secrete actively. For example, many girls have heavy body hair, mustaches, and generally have oily skin. Certain diseases, such as polycystic ovary syndrome, adrenal hyperplasia, or tumors, can lead to excessive secretion of androgens and accelerate sebum secretion.

High-sugar, high-cholesterol foods can also increase androgen levels (sugar can provide raw materials for the synthesis of cholesterol, and cholesterol is a precursor for androgen synthesis).

Androgen receptor sensitivity can also cause active sebum secretion, but there is currently no research showing how to block this receptor (or there has been research but I haven't seen it yet).

2. Temperature

Temperature can significantly affect sebum secretion. The higher the temperature, the more active the sebaceous glands secrete, but the reason why there is such a relationship is still unclear. People in the south tend to have oily skin, while people in the north tend to have less oily skin. Their skin tends to be oily in the summer and dry in the winter. Looking at the computer may cause the oil secretion to increase, because the accumulated heat emitted by the computer screen cannot be underestimated.

3. Reflex oil secretion

There is a view that the skin undergoes "reflexive oil secretion" when sebum is over-cleansed or the skin is not sufficiently hydrated. This may happen to people who over-cleanse or have dehydrated skin. However, this hypothesis has not yet been confirmed by rigorous research. If this hypothesis is true, then good hydration and moisturizing can reduce oil secretion.

4. Impact of parasites

Last year, I speculated that lipophilic organisms, such as Malassezia and Demodex, might release certain metabolites to promote the secretion of oil in order to create a better living environment for themselves. Preliminary observations showed that the growth rate of whiteheads is related to the rate of oil secretion, and a large number of fungi can be found in whiteheads; after taking measures to inhibit fungi, the growth rate of whiteheads (oil) decreased. However, this hypothesis needs to be confirmed by studies with larger sample sizes. Another possibility is that the body has sensed the adverse effects of these parasites and wants to speed up their excretion, thus actively accelerating oil secretion.

This year I think this may make sense. A good friend of mine more than ten years ago had perfect skin, neither oily nor dry, and zero pores, until I saw her last year. Unexpectedly, when I saw her again this year, I found that she had obvious seborrheic problems and orange peel-like pores appeared on the sides of her nose. This shows that the pores and oil secretion may be acquired.

(V) The stratum corneum is too thin

This hypothesis first appeared on the scalp, believing that the stratum corneum has the function of an "oil-absorbing sponge". When the stratum corneum is too thin, the lipid cannot be absorbed and emulsified well and will float on the surface, causing obvious oiliness. It is proven that some people whose skin is not oily may suddenly have oily skin and even develop symptoms of seborrheic dermatitis after excessive cleansing and exfoliation. However, whether it is caused by the loss of the "sponge" or the abnormal reproduction of microorganisms after the injury requires further research.

Second, the main method to reduce oily shine

Taking into account the principles and hypotheses described above, a comprehensive strategy for oil control can be developed:

① Adsorption: Mainly powder, which absorbs oil to achieve a matte effect. Some users have reported that using pearl powder on the skin has a very good effect. Seaweed polysaccharides can eliminate facial shine. Researchers extracted a polysaccharide EPS Seamat from seaweed in the French Gulf of Aber-Wrac'h. It can absorb and wrap excess sebum. Tests have shown that it can eliminate facial oiliness within 1 hour after use and the effect lasts for 8 hours. This raw material does not seem to have been applied to specific products yet. The adsorbed powder should be sufficiently fine, because the adsorption capacity is related to its specific surface area, and finer powders have larger specific surface area.

②Astringency: Combine with protein to denature and coagulate it, produce a sense of astringency, and achieve surface improvement, such as alcohol and tannin (tannic acid). This can be confirmed by doing some small experiments. However, this is only a temporary solution and does not address the root cause.

③ Unclogging: Remove grease and keratin plugs, and unclog pores, such as detergents and salicylic acid.

④ Reduce sebum secretion: such as Vb6, VB3 (niacinamide, such as Olay), VA, Salvia miltiorrhiza, Anemarrhena asphodeloides, Dalbergia cochinchinensis, etc. can inhibit the activity of 5α-reductase, reduce the production of DHT, and thus reduce oil secretion (when I was making the Manling formula, I mainly considered these aspects). Vb6, VB3, and VA are also effective when taken orally.

⑤ Anti-fungal, inhibiting Demodex, etc., such as using Caile lotion, ZPT, selenium disulfide, sulfur soap, Manling essence, etc. It is more suitable for people who are prone to seborrheic dermatitis.

⑥ Strong oil secretion should be screened for endocrine diseases to rule out.

⑦Dietary adjustment: Eat more vegetarian and soy products, less meat, less oil and less sugar. Eat more foods containing VB and VA, such as whole grains, carrots, etc.; a study shows that taking collagen orally can also reduce sebum secretion and increase skin moisture. In terms of oral medications, doctors will use tanshinone, retinoic acid, etc. to reduce oil secretion. Retinoic acid has significant side effects and should be used strictly according to doctor's advice.

⑧ Cooling down the skin: For example, place a sponge soaked in water in front of the computer to keep the environment moist and cool down the skin; use a cool towel for cold compresses, etc.

⑨Oil-absorbing facial tissue: As a temporary method, it is sometimes indispensable.

⑩Avoid excessive exfoliation.

3. FAQ

1. What does it mean when the outside is oily and the inside is dry?

“Oily on the outside, dry on the inside” skin has well-developed sebaceous glands that can secrete a lot of oil and large pores, but also has insufficient water retention due to skin barrier damage. Therefore, although it is oily, it often feels dry. Others suffer from seborrheic dermatitis (often referred to as oily sensitive skin). Because of the oil, there is often a tendency to over-cleanse, which further weakens the skin's ability to retain water, making it drier. For this type of skin, we should first distinguish the cause: is it simply dehydration or seborrheic dermatitis? If it is the former, you can first clean and control oil, then moisturize and condition gradually; if it is the latter, you should solve the dermatitis problem first, otherwise it will be difficult to improve.

2. What should I do if my nose and sides are very oily?

This is what combination skin is like, so it is particularly necessary to popularize the practice of zone care. The skin qualities of the T zone and the V zone are very different. In the T zone, you should focus on oil control, cleansing and exfoliation. If you use these in the V zone, it will easily damage the skin. For combination and sensitive skin, the V zone focuses on repair and different products are used. You can choose a facial cleanser with stronger cleansing power made from amino acids. When washing your face, focus on the T-zone and lightly brush the V-zone. Blackheads will also be significantly reduced through the combined treatment of oil control and cleansing.

3. Why does the oiliness increase when looking at the computer?

This is mainly caused by the heat emitted by the computer, which causes the local ambient temperature to rise, and the time is particularly long. Furthermore, people sitting in front of a computer usually put themselves in a state of tension, with their brains working at high speed, blood flowing through the head increasing, and metabolism being vigorous, which may increase the temperature of the facial skin (hypothesis, to be studied), thereby promoting the secretion of sebum.

4. Can I use oil-absorbing paper?

The secretion of oil by the skin is controlled by factors such as the number of sebaceous glands, ambient temperature, and hormone levels. Indeed, if there is a lack of oil and the sebaceous glands are well developed, the sebaceous glands will be stimulated to secrete oil. However, oil-absorbing paper can only absorb the oil on the surface and will not cause sebum deficiency, so there is no need to worry. But the main problem is that oil-absorbing paper only treats the symptoms and not the root cause.

5. There are a lot of oil particles in the pores. What is going on?

This is a keratin plug, whose basic structure is a sebum sac wrapped in keratin, but its specific composition and cause of occurrence have not yet been clearly studied. Hopefully this mystery can be solved in the future.