What is best not to combine with creatine?
Combining creatine with caffeine powder adds nothing to your performance and increases the risk of gastrointestinal complaints; ready-made pre-workout blends with many ingredients carry additional risks due to possible contamination and unknown long-term effects.
Combining creatine with caffeine adds nothing to your performance. After five days of creatine loading with extra caffeine in powder form, there was no measurable benefit to strength or sprinting compared with creatine alone. After six weeks of strength training, the combination also produced no better results for muscle mass, strength or endurance than creatine by itself; creatine alone showed a small improvement in knee extensor thickness.
There is one small signal that creatine nitrate combined with caffeine slightly improves cognitive performance on a colour-naming task, but that study included only 12 participants and the effect was small. That is too little to draw any conclusions from.
On top of that, there is a concrete safety concern. In the five-day loading study, nearly one third of participants in the creatine plus caffeine powder group experienced mild gastrointestinal complaints. In the groups that combined creatine with coffee, or took creatine alone, nobody reported any side effects. If you want to use creatine, loose caffeine powder is therefore the most stomach-sensitive combination. Coffee does not appear to be a problem in this regard.
A broader warning applies to ready-made pre-workout products that combine creatine with dozens of other ingredients. Research shows that around 90 percent of such sports supplements contain traces of hormone-disrupting substances, and half are contaminated with unwanted compounds. Most studies on such products lasted fewer than eight weeks, meaning virtually nothing is known about long-term effects. You also cannot tell which ingredient is causing which effect. Simply buy creatine monohydrate on its own, as a powder or capsules: the label says 'creatine monohydrate' and nothing else of note. More ingredients on the label are not an advantage; they give you less control over what you are taking and you pay more for them.
This answer is based on four randomised studies and four reviews. The randomised studies are relatively small (the smallest has 12 participants) and last fewer than eight weeks; the reviews summarise the broader safety literature. The findings on the lack of synergy between creatine and caffeine are reasonably consistent, but the small sample sizes make it difficult to measure rare side effects reliably. Good research on long-term combinations is almost entirely absent.
Which supplements are best avoided when taking blood thinners?
Ginkgo biloba, ginger, garlic, cranberry and St John's wort are best known as risky combinations with warfarin and similar blood thinners. Tell your doctor or pharmacist which supplements you use, because even seemingly harmless products can affect the balance of blood clotting.
Which supplements or medications are best not combined with NAD+?
The combination of NAD+ supplements, particularly nicotinamide, with platinum-based chemotherapy is the most concrete reason for caution. For other interactions the indications are preliminary, but worth discussing if you use multiple substances.
Why don't doctors always recommend creatine?
Creatine is well supported for building muscle during strength training and is safe for healthy people. For other goals, such as mental health complaints or fat loss, the evidence is too mixed to base a recommendation on.
Do you need to do a loading phase with creatine?
A loading phase is not necessary, but it does speed up the build-up of creatine in your muscles. Choose a loading phase if you want fast results, or simply take 3 to 5 grams daily if you have more patience.
What is the best way to use creatine?
Creatine works best in combination with strength training: optionally start with a loading phase of 20 grams per day for 5 days and then maintain with 2 to 5 grams per day. If you have a kidney condition, discuss it with your doctor first.
Does creatine work better with carbohydrates?
Carbohydrates probably increase the uptake of creatine into the muscle cell via insulin, but when compared against a placebo in research this does not translate into better performance. Add carbohydrates if you want to load, but do not automatically count on extra training results.