Your blood is rich in red cells that contain haemoglobin, a protein that carries oxygen from the lungs to the rest of the body.
A key part of haemoglobin is iron. Iron is an important dietary mineral found in the foods we eat and is essential for your body to do what it’s supposed to do.
Our bodies need iron to make haemoglobin, and for our general health and wellbeing.
Let’s take a closer look at iron and haemoglobin when it comes to donating blood.
For some people, iron levels can drop over time. This may lead to iron deficiency or low haemoglobin (anaemia) — or both.
Women aged 18-45 are particularly susceptible to becoming low in iron, so we recommend iron supplements if they’re giving blood. We do this because your safety is important to us.
During a blood donation you give about 250mg of iron with your red cells, so it’s important your iron levels aren’t low to begin with.
We check your haemoglobin before every donation to make sure that it’s safe for you to donate. If your haemoglobin level is below a certain range, you won’t be able to give blood.
Measuring your haemoglobin
We measure your haemoglobin for your health, which is really important to us.
When you give blood, you’re giving red cells, so you’ll have a temporary drop in your haemoglobin level. We need to make sure your haemoglobin is high enough for you to donate safely.
We’ll do this before each donation. In most of our blood donor centres, we collect a few blood drops from a finger prick, but in some centres we use a blood sample collected from the vein just before the donation.
Note: We don’t usually test your iron level before a donation. We only send a blood sample for iron testing if your haemoglobin level is below the minimum level or if you have a greater than 20g/L drop in haemoglobin since your last visit.
If your haemoglobin is below a certain range, you won’t be able to give blood. We'll send a blood sample to our lab to measure your ferritin levels, which tells us your iron levels.
We’ll send you a letter with the results. If you have low haemoglobin, low iron or both, we’ll recommend that you see your doctor and we'll send you a letter you can take with you.
So what's a safe level for donating?
The minimum haemoglobin level needed to donate blood is 120g/L (grams per litre) for women and 130g/L for men.
The minimum haemoglobin level to donate plasma or platelets is 115g/L for women and 125g/L for men. It’s lower for plasma and platelets because you get your red blood cells back during the donation. Find out more about donating plasma.
Iron is needed for your body to make haemoglobin and to donate, you need to meet the minimum haemoglobin level. We’ll check your levels when you come in. Talk to your GP if you’re unsure about your iron levels or if it’s safe for you to donate.
Maintaining healthy iron levels
The time it takes to replace iron through your diet varies and will depend on your diet and general health. Here are some tips:
- Aim to have a healthy, iron-enriched diet.
- For some donors, it can take longer than 12 weeks to replace the iron through diet. For women aged 18-45, we recommend taking a short course of iron supplements after your donation – check out the following section for more details.
- If you’re a regular blood donor, you may like to alternate between giving blood and plasma. That’s because we return your red blood cells to you when you give plasma, so you’re not giving as much iron.
- If you’re planning for pregnancy, it’s especially important that you build and maintain healthy iron levels.
- Speak with your doctor if you have any concerns about your iron levels or want to discuss the best donation frequency for you.
Taking iron supplements
If you’re a woman aged 18-45 and donating blood, we recommend that you take a short course of iron supplements after your donation. For more information, check out the flyer below or browse these frequently asked questions if you're not sure about what iron supplements to take, or when.
- You’ve recommended iron supplements to me. Can I use a multivitamin instead?
While a lot of multivitamins do contain iron, most only have a small dose of elemental iron (e.g. 5mg per tablet). Multivitamins wouldn’t replace the iron you donated as quickly as one of the supplements we recommend.
If you’d prefer to use a lower dose iron supplement, speak with your pharmacist.
- Why do I have to tell the pharmacist if I’m taking medications?
Iron supplements can interact with some medicines when taken at the same time. The iron may change the effectiveness of your medication, or your medication may affect how your body absorbs the iron.
Your pharmacist can let you know if you need to take your iron supplement at a different time of day to your medicine.
- Why do I have to tell the pharmacist if I’m taking other supplements?
Many supplements already contain iron, including those for pre-pregnancy. Your pharmacist can let you know how much iron, if any, is in your current supplement and help you decide if you need more to help replace what you’ve given during donation.
If you’re taking a pre-pregnancy supplement, you should continue taking it — it also contains folate.
- Why isn’t Lifeblood providing or paying for the supplements?
Australian legislation doesn’t allow us to provide iron to donors. Only pharmacies can dispense these supplements.
- Why don’t you recommend taking iron supplements after a plasma donation?
When you give plasma, your red cells are returned to you. That means you don't give as much iron in your donation, and our research shows that plasma donors usually aren’t at an increased risk of low iron.
If I don’t menstruate and haven’t been pregnant recently, do I still need to take the iron?
We’re recommending iron for all women aged 18-45 regardless of menstrual or pregnancy history. Speak with your doctor if you’re not sure about your iron requirements.
- If I take iron can I donate blood more often?
No. For your health and wellbeing, you still need to wait 12 weeks between blood donations. It’s a different story for plasma, though! Learn more about giving plasma.
- My haemoglobin is normal, do I still need to take iron?
After donating, your body uses iron to make haemoglobin for new red cells. Your body will absorb the iron it needs from diet, but it can take months to get back to the level it was. A short course of iron supplements can help you maintain healthy iron levels, keeping you feeling your absolute best.
- Should I donate blood if I can’t, or choose not to, take iron supplements?
It’s really up to you, but if your haemoglobin levels start to drop, we may ask you to wait between donations.
It’s important that you consider your own health and wellbeing. If you feel blood donation isn't for you and you still want to help (thanks for being so passionate!), you could try giving plasma instead which has a smaller iron loss. Plasma is a powerful part of blood that can be used in 18 different life-giving ways, and demand is at an all-time high. Find out more about plasma today.