Period Colors: Black, Pink, Orange... The Meaning Guide!

You change your period protection and surprise! It's not the usual red you expected. Black? Pink? Orange? You Google "black period blood" and come across forums where some people are alarmed while others are reassured. So what's really going on?

The color of your period tells a story, that of your menstrual flow, from its journey from your uterus to your sanitary protection. From bright red to deep black, each shade has its meaning. Some colors are perfectly normal, others require a little attention, and a few warrant a doctor's visit. This guide deciphers all the possible colors of your period, with clear scientific explanations and without unnecessary dramatization.

Summary Table: Deciphering the Color of Your Period

Before you dietailleFor each color, this chart gives you a quick overview of what each shade means. Keep in mind that these are general trends and your body is unique.

Color	Usual texture	Meaning	Cycle timing
Bright red	Fluid, liquid	Fresh blood, normal and healthy flow	Mid-cycle (D2-D4)
Dark red	Slightly thick	Oxidized blood, slow flow	Start or end (D1, D5-D7)
Brown/brown	Thick, sometimes lumpy	Very oxidized, stagnant blood	Start/end, upon waking
Noir	Very thick, compact	Maximum oxidation, old blood	Any beginning or any end
Light pink	Fluid, diluted	Blood mixed with cervical mucus	Light flow (D1, D6-D7)
Orange	Variable	⚠️ Possible infection	Anytime
Grey	Watery, smelly	⚠️ Infection or miscarriage	Anytime

Why Does Menstrual Blood Change Color?

To understand color variations, we must first grasp a simple but fundamental scientific concept: oxidationIt is this which explains 90% of the changes in color that you observe.

Oxidation: The Determining Factor

When menstrual blood leaves your uterus, it comes into contact with oxygen in the air. This contact triggers a chemical reaction called oxidation. Hemoglobin, the protein that carries oxygen in your red blood cells and gives blood its red color, reacts with the ambient oxygen and gradually breaks down.

The longer it takes for blood to leave your uterus and vagina, the more it oxidizes and the darker its color becomes. It's exactly the same as a cut apple turning brown in the open air.

Other Factors That Influence Color

Beyond oxidation, other elements affect the color of your period.

• The speed of the flow : A heavy flow expels blood quickly, it remains bright red. A light flow lets it stagnate, it darkens
• Mixing with other fluids : Cervical mucus, vaginal secretions, which lighten the color
• The composition of menstrual blood : It contains not only blood but also endometrial cells, enzymes, mucus
• Your hemoglobin level : Anemia makes the blood paler because it contains less iron.
• Uterine contractions The stronger they are, the faster the blood comes out and stays red.

Bright Red: "Normal" Menstrual Blood

This is the reference color, the one we see in representations (even if the ads continue to show us blue liquid). The bright red indicates that the blood is fresh and it quickly leaves your uterus without having time to oxidize. This is typical of the days when your flow is heaviest.

Why It's Bright Red

Menstrual blood contains oxygen-laden hemoglobin. When it's expelled quickly, this hemoglobin remains intact and retains its characteristic bright red color. During your days of heavy flow, uterine contractions are stronger and expel blood efficiently.

Brown, Brown, Black: Oxidation at Work

It's the number one concern in Google searches. Thousands of women type in "black period blood" or "why is my period black" every month. The answer is simple and reassuring in the majority of cases: it is oxidized blood, "old" blood that has stagnated.

Why This Dark Color

When blood takes longer to leave your uterus, it remains exposed to oxygen longer. Hemoglobin gradually breaks down, iron oxidizes (like rust), and the blood turns from red to brown to black. The water in the blood also evaporates, concentrating the color.

This phenomenon is particularly frequent:

• At the very beginning of menstruation (D1) : The blood may have started to collect the day before, it appears brown in the morning
• At the end of menstruation (D5-7) : The flow slows down, the blood takes its time to come out
• Wake : Blood stagnated all night in a lying position
• With a very light flow : The less volume there is, the more visible the oxidation is.

Pale Pink: Dilution and Other Causes

Pink periods are often cause for concern, but in most cases, it's simply the result of red menstrual blood mixing with other clear vaginal fluids. The combination of blood, cervical mucus, and vaginal secretions creates this pinkish tint.

Benign Causes of Pink Blood

Causes Requiring Attention

If pink blood persists cycle after cycle or is accompanied by other symptoms, several medical causes are possible.

• Iron deficiency anemia : Iron gives blood its red color. A lack of iron = paler blood. Associated symptoms: chronic fatigue, dizziness, pallor, brittle nails
• Low estrogen levels : May be related to perimenopause, hormonal disorder, or inadequate contraception
• Polycystic ovary syndrome (PCOS) : Hormonal imbalance that can cause irregular pink bleeding
• Sexually transmitted infections : Some STIs cause pink discharge between periods.

Orange: Infection Alert Signal

Orange periods are never a "normal" color. If you observe this shade, make an appointment quickly with your gynecologist or doctorIn the vast majority of cases, this indicates a vaginal or cervical infection.

Why This Orange Color

Red menstrual blood mixed with infected vaginal discharge (yellowish or greenish) gives this characteristic orange tint. The most common infections are:

• Bacterial vaginosis : Imbalance of vaginal flora, characteristic fishy odor
• Trichomoniasis : Parasitic STI, yellowish foamy discharge, intense itching
• Chlamydia : Bacterial STI often asymptomatic at first
• Cervicitis : Inflammation of the cervix of infectious origin

Gray: Medical Emergency

Gray discharge during or outside of menstruation is always a warning sign. Consult urgentlyThis color is never benign and requires prompt medical examination.

Possible causes

• Severe bacterial vaginosis : Vaginal infection with major imbalance of flora
• Miscarriage : If you are pregnant, gray discharge with tissue may indicate pregnancy loss.
• Pelvic infection : Infection that has spread to the uterus or fallopian tubes
• Forgotten foreign body : Tampon, cup or other object left in the vagina too long

Dark Red and Burgundy: In Between

This shade is halfway between bright red (fresh blood) and brown (highly oxidized blood). It is a completely normal color that simply indicates that the blood has begun to oxidize, without reaching the stage of "old" blood.

You typically observe it:

• In the morning upon waking (the blood has stagnated during the night)
• At the start of your period when the flow starts gently
• At the end of your period when the flow slows down
• With clots of taille normal (small pieces of endometrium)

No need to worry, it's just proof that your flow isn't at its peak and that the blood has had a few hours to start oxidizing.

When Should You Be Worried About Period Color?

Most color variations are physiological and normal. However, some signs warrant medical consultation to rule out an underlying health problem.

Signal	Urgency	Possible cause
Orange or grayish discharge	Fast	Infection (vaginosis, STI)
Black blood throughout the cycle	Moderate	Possible obstruction
Bright red + period > 8 days	Moderate	Menorrhagia, fibroids
Pale pink + chronic fatigue	Moderate	Iron deficiency anemia
Dark discharge + severe pain	Fast	Ectopic pregnancy, infection

Rule Color and Texture: The Duo to Watch

Color alone doesn't tell the whole story. The texture of your period provides important additional information about your menstrual health.

Fluid and Liquid

This is the normal texture of menstrual blood, similar to blood from a cut. Thin blood indicates an active flow and good flow.

Thick or Slimy

At the end of your period or upon waking, your blood may be thicker. This is due to the mixture with endometrial cells and a higher concentration (partial evaporation). As long as this is occasional, it's normal.

With Clots

Clots are pieces of the endometrium (uterine lining) that break off. This is a normal phenomenon.

Aqueous or Very Dilute

If your period looks like tinted water rather than blood, this may indicate severe anemia (low iron = blood with less hemoglobin). Have your iron levels checked with a blood test.

Factors That Influence Period Color

Beyond physiological causes, several elements of your life can modify the appearance of your menstruation.

Hormonal Contraception

Hormonal contraceptives (pill, implant, patch) alter the thickness of the endometrium and the amount of blood loss. The result: periods that are often lighter (pink), lighter, and shorter. This is an expected and desired effect.

Age and Hormonal Transitions

Your periods naturally change throughout your life.

• In adolescence : Irregular cycles, colors vary from one month to the next, while the hormonal axis regulates itself
• After pregnancy : Gradual return to normal in 3-6 months, periods sometimes heavier or different than before
• In perimenopause (40-50 years old) : Irregular cycles, significant variations in color and flow from one cycle to another due to hormonal fluctuations
• With a copper IUD : Periods often heavier and redder (large quantities of fresh blood)

Diet and Hydration

A diet low in iron can gradually lead to anemia and lighten the color of the blood. Conversely, good hydration maintains blood volume and can make periods slightly lighter.

What Science Says About Menstrual Blood

Menstrual blood isn't "pure" blood like the blood that flows through your veins. It's a complex mixture that accounts for its variations in color and texture.

Composition of Menstrual Blood

Scientific studies have shown that the hemoglobin level in menstrual blood (2-4 g/dL) is significantly lower than that of circulating blood (10-15 g/dL). This is why menstrual blood is often less bright red than blood from an injury.

Normal Blood Loss Volume

Over a full cycle, a woman loses on average 30 to 40 ml of blood, or about 2 to 3 tablespoons. This is much less than you might think! Beyond 80 ml per cycle, we speak of menorrhagia (bleeding periods).

Sources & Scientific References